5 Census Data Wrangling
5.1 Overview
Once we identify the appropriate access metric to use, we can now include contextual data to add nuance to our findings. This can help identify if any specific disparities in access exist for certain groups of people or if there are any specific factors that can help explain the spatial patterns. Such datasets are often sourced from the US Census Bureau. The American Community Survey (ACS) is an ongoing survey that provides data every year with 1 and 5-year estimates. We generally recommend using the 5-year estimates as these multiperiod estimates tend to have increased statistical reliability as compared to the 1-year numbers, especially for less populated areas and small population subgroups.
In this tutorial we demonstrate how to explore and download most commonly used population datasets from the same, with and without spatial components. Please note this tutorial focuses only on the American Community Survey datasets available via the Census Bureau API. More details about using tidycensus, with tutorials generated by package authors, can be found here.
Our objectives are to:
- Download census data through the Census API
- Download census boundaries thorough the Census API
- Wrangle, clean and merge data for further integration
5.2 Environment Setup
To replicate the codes & functions illustrated in this tutorial, you’ll need to have R and RStudio downloaded and installed on your system. This tutorial assumes some familiarity with the R programming language.
5.2.1 Input/Output
We will not be using an external input for this exercise.
Our output will be two sets of files:
- CSV file and shapefile with Race Data distributions at county level for the state of Illinois.
- and CSV file and shapefile with Population and Per Capita Income for the zipcodes within the city of Chicago for 2018.
5.2.2 Load Libraries
We will use the following packages in this tutorial:
sf: to read/write sf (spatial) objectstidycensus: to download census variables using ACS APItidyverse: to manipulate and clean datatigris: to download census tiger shapefiles
Load the required libraries.
5.3 Enable Census API Key
To be able to use the Census API, we need to signup for an API key. This key effectively is a string identifier for the server to communicate with your machine. A key can be obtained using an email from here. Once we get the key, we can install it by running the code below.
In instances where we might not want to save our key in the .Renviron - for example, when using a shared computer, we can always reinstall the same key using the code above but with install = FALSE.
To check an already installed census API key, run
5.4 Load Data Dynamically
We can now start using the tidycensus package to download population based datasets from the US Census Bureau. In this tutorial, we will be covering methods to download data at the state, county, zip and census tract levels. We will also be covering methods to download the data with and without the geometry feature of the geographic entities.
To download a particular variable or table using tidycensus, we need the relevant variable ID, which one can check by reviewing the variables available via load_variables() function. For details on exploring the variables available via the tidycensus & to get their identifiers, check the Explore variables available section in Appendix.
We can now download the variables using get_acs() function. Given ACS data is based of an annual sample, the datapoints are available as an estimate with a margin or error (moe). The package provides both values for any requested variable in the tidy format.
For the examples covered in this tutorial, the 4 main inputs for get_acs() function are:
geography- for what scale to source the data for (state / county / tract / zcta)variables- character string or a vector of character strings of variable IDs to sourceyear- the year to source the data forgeometry- whether or not to include the geometry feature in the tibble. (TRUE / FALSE)
5.4.1 State Level
To get data for only a specific state, we can add state = sampleStateName.
stateDf <- get_acs(geography = 'state', variables = c(totPop18 = "B01001_001",
hispanic ="B03003_003",
notHispanic = "B03003_002",
white = "B02001_002",
afrAm = "B02001_003",
asian = "B02001_005"),
year = 2018, geometry = FALSE)
head(stateDf)## # A tibble: 6 x 5
## GEOID NAME variable estimate moe
## <chr> <chr> <chr> <dbl> <dbl>
## 1 01 Alabama totPop18 4864680 NA
## 2 01 Alabama white 3317453 3345
## 3 01 Alabama afrAm 1293186 2745
## 4 01 Alabama asian 64609 1251
## 5 01 Alabama notHispanic 4661534 393
## 6 01 Alabama hispanic 203146 393
As we can see the data is available in the tidy format. We can use other tools in the tidyverse universe to clean and manipulate it.
stateDf <- stateDf %>%
select(GEOID, NAME, variable, estimate) %>%
spread(variable, estimate) %>%
mutate(hispPr18 = hispanic/totPop18, WhitePr18 = white/totPop18,
AfrAmPr18 = afrAm/totPop18, AsianPr18 = asian/totPop18) %>%
select(GEOID,totPop18,hispPr18,WhitePr18,AfrAmPr18, AsianPr18)
head(stateDf)## # A tibble: 6 x 6
## GEOID totPop18 hispPr18 WhitePr18 AfrAmPr18 AsianPr18
## <chr> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 01 4864680 0.0418 0.682 0.266 0.0133
## 2 02 738516 0.0693 0.648 0.0327 0.0630
## 3 04 6946685 0.311 0.772 0.0439 0.0329
## 4 05 2990671 0.0732 0.770 0.154 0.0147
## 5 06 39148760 0.389 0.601 0.0579 0.143
## 6 08 5531141 0.214 0.842 0.0412 0.0312
5.4.2 County Level
Similarly, for county level
- use
geometry = countyto download for all counties in the U.S. - use
geometry = county, state = sampleStateNamefor all counties within a state - use
geometry = county, state = sampleStateName, county = sampleCountyNamefor a specific county
countyDf <- get_acs(geography = 'county', variables = c(totPop18 = "B01001_001",
hispanic ="B03003_003",
notHispanic = "B03003_002",
white = "B02001_002",
afrAm = "B02001_003",
asian = "B02001_005"),
year = 2018, state = 'IL', geometry = FALSE) %>%
select(GEOID, NAME, variable, estimate) %>%
spread(variable, estimate) %>%
mutate(hispPr18 = hispanic/totPop18, WhitePr18 = white/totPop18,
AfrAmPr18 = afrAm/totPop18, AsianPr18 = asian/totPop18) %>%
select(GEOID,totPop18,hispPr18,WhitePr18,AfrAmPr18, AsianPr18)
head(countyDf)## # A tibble: 6 x 6
## GEOID totPop18 hispPr18 WhitePr18 AfrAmPr18 AsianPr18
## <chr> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 17001 66427 0.0154 0.931 0.0408 0.00813
## 2 17003 6532 0.0112 0.624 0.332 0.000919
## 3 17005 16712 0.0346 0.909 0.0624 0.0117
## 4 17007 53606 0.214 0.874 0.0222 0.0118
## 5 17009 6675 0.0428 0.774 0.204 0.00554
## 6 17011 33381 0.0897 0.936 0.00932 0.00866
And now we can save the dataset in CSV file using code below.
5.4.3 Census Tract Level
For census tract level, at the minimum stateName needs to be provided.
- use
geometry = tract, state = sampleStateNameto download all tracts within a state - use
geometry = tract, state = sampleStateName, county = sampleCountyNameto download all tracts within a specific county
tractDf <- get_acs(geography = 'tract',variables = c(totPop18 = "B01001_001",
hispanic ="B03003_003",
notHispanic = "B03003_002",
white = "B02001_002",
afrAm = "B02001_003",
asian = "B02001_005"),
year = 2018, state = 'IL', geometry = FALSE) %>%
select(GEOID, NAME, variable, estimate) %>%
spread(variable, estimate) %>%
mutate(hispPr18 = hispanic/totPop18, WhitePr18 = white/totPop18,
AfrAmPr18 = afrAm/totPop18, AsianPr18 = asian/totPop18) %>%
select(GEOID,totPop18,hispPr18,WhitePr18,AfrAmPr18, AsianPr18)
head(tractDf)5.4.4 Zipcode Level
For zipcode level, use geometry = zcta. Given zips cross county/state lines, zcta data is only available for the entire U.S.
zctaDf <- get_acs(geography = 'zcta',variables = c(totPop18 = "B01001_001",
hispanic ="B03003_003",
notHispanic = "B03003_002",
white = "B02001_002",
afrAm = "B02001_003",
asian = "B02001_005"),
year = 2018, geometry = FALSE) %>%
select(GEOID, NAME, variable, estimate) %>%
spread(variable, estimate) %>%
mutate(hispPr18 = hispanic/totPop18, WhitePr18 = white/totPop18,
AfrAmPr18 = afrAm/totPop18, AsianPr18 = asian/totPop18) %>%
select(GEOID,totPop18,hispPr18,WhitePr18,AfrAmPr18, AsianPr18)Inspect the data.
## # A tibble: 6 x 6
## GEOID totPop18 hispPr18 WhitePr18 AfrAmPr18 AsianPr18
## <chr> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 00601 17242 0.997 0.755 0.00841 0.000174
## 2 00602 38442 0.935 0.794 0.0278 0
## 3 00603 48814 0.974 0.765 0.0395 0.00746
## 4 00606 6437 0.998 0.408 0.0231 0
## 5 00610 27073 0.962 0.755 0.0257 0
## 6 00612 60303 0.993 0.807 0.0456 0.00985
## [1] 33120 6
Given zipcode data can only be sourced for the entire nation, after sourcing it, we can filter them for certain region,e.g. below we can filter for zipcodes in Chicago by using str_detect and then save it to a .csv file.
zipChicagoDf <- get_acs(geography = 'zcta', variables = c(perCapInc = "DP03_0088"),year = 2018, geometry = FALSE) %>%
select(GEOID, NAME, variable, estimate) %>%
filter(str_detect( GEOID,"^606")) %>%
spread(variable, estimate) %>%
select(GEOID, perCapInc)## Getting data from the 2014-2018 5-year ACS
## Using the ACS Data Profile
For more details on the other geographies available via the tidycensus package, check here.
5.5 Get Geometry
Geometry/Geographic Boundaries are one of the key features for American Community Survey Data as they set up the framework for data collection and estimation. While boundaries don’t change often, updates do occur from time to time and census data for a specific year generally tends to use the boundaries available at the beginning of that year. Most ACS products since 2010 reflect the 2010 Census Geographic Definitions. Given certain boundaries like congressional districts, census tracts & block groups are updated after every decennial census, products for year 2009 and earlier will have significantly different boundaries from that in 2010. We recommend using IPUMS datasets to generate estimates for years prior to 2010.
The datasets downloaded so far did not have a spatial geometry feature attached to them. To run any spatial analysis on the race data above, we would need to join these dataframes to another spatially-enabled sf object. We can do so by joining on the ‘GEOID’ or any other identifier. We can download the geometry information using two methods :
- using
tigris - using
tidycensus
5.5.1 Using tigris
To download and use the Tiger Shapefiles shared by the US Census Bureau we will use the tigris package. Set cb = TRUE to get generalized files, these don’t have high resolution details and hence are smaller in size.
yeartoFetch <- 2018
stateShp <- states(year = yeartoFetch, cb = TRUE)
countyShp <- counties(year = yeartoFetch, state = 'IL', cb = TRUE)
tractShp <- tracts(state = 'IL',year = yeartoFetch, cb = TRUE)
zctaShp <- zctas(year = yeartoFetch, cb = TRUE) Now we can merge these geometry files with the race data downloaded in previous section.
For states:
# check object types & identifier variable type
# str(stateShp)
# str(stateDf)
stateShp <- merge(stateShp, stateDf, by.x = 'STATEFP', by.y = 'GEOID', all.x = TRUE)
head(stateShp)## Simple feature collection with 6 features and 14 fields
## geometry type: MULTIPOLYGON
## dimension: XY
## bbox: xmin: -179.1489 ymin: 30.22333 xmax: 179.7785 ymax: 71.36516
## CRS: 4269
## STATEFP STATENS AFFGEOID GEOID STUSPS NAME LSAD ALAND AWATER totPop18
## 1 01 01779775 0400000US01 01 AL Alabama 00 1.311740e+11 4593327154 4864680
## 2 02 01785533 0400000US02 02 AK Alaska 00 1.478840e+12 245481577452 738516
## 3 04 01779777 0400000US04 04 AZ Arizona 00 2.941986e+11 1027337603 6946685
## 4 05 00068085 0400000US05 05 AR Arkansas 00 1.347689e+11 2962859592 2990671
## 5 06 01779778 0400000US06 06 CA California 00 4.035039e+11 20463871877 39148760
## 6 08 01779779 0400000US08 08 CO Colorado 00 2.684229e+11 1181621593 5531141
## hispPr18 WhitePr18 AfrAmPr18 AsianPr18 geometry
## 1 0.04175938 0.6819468 0.26583167 0.01328124 MULTIPOLYGON (((-88.05338 3...
## 2 0.06930926 0.6483732 0.03267228 0.06303993 MULTIPOLYGON (((179.4825 51...
## 3 0.31141645 0.7721872 0.04394312 0.03294910 MULTIPOLYGON (((-114.8163 3...
## 4 0.07324510 0.7700192 0.15413598 0.01470840 MULTIPOLYGON (((-94.61783 3...
## 5 0.38881377 0.6010169 0.05792968 0.14315496 MULTIPOLYGON (((-118.6044 3...
## 6 0.21420427 0.8417041 0.04120994 0.03122231 MULTIPOLYGON (((-109.0603 3...
Similarly for counties, zctas & census tracts we can use the code below and save the shapefiles.
countyShp <- merge(countyShp, countyDf, by.x = 'GEOID', by.y = 'GEOID', all.x = TRUE) %>%
select(GEOID,totPop18,hispPr18,WhitePr18,AfrAmPr18, AsianPr18)
tractShp <- merge(tractShp, tractDf, by.x = 'GEOID', by.y = 'GEOID', all.x = TRUE) %>%
select(GEOID,totPop18,hispPr18,WhitePr18,AfrAmPr18, AsianPr18)
zctaShp <- merge(zctaShp, zctaDf, by.x = 'GEOID10', by.y = 'GEOID', all.x = TRUE)%>%
select(GEOID10,totPop18,hispPr18,WhitePr18,AfrAmPr18, AsianPr18)
write_sf(countyShp, "data/Chicago_Zip_PCI_18.shp")Now we can finally filter the zipcodes for Chicago. and save the census tract results with geometry in a shapefile using write_sf.
5.5.2 Using tidycensus
The previous method adds an additional step of using tigris package to download the shapefile.
The tidycensus package already has the wrapper for invoking tigris within the get_acs() function, and we can simply download the dataset with geometry feature by using geometry = TRUE.
The wrapper adds the geometry information to each variable sourced, and the file size can become large in the intermediary steps and slow down the performance, even though the data is in tidy format. So if you are looking to download many variables with large API requests, we recommend downloading the dataset without geometry information and then downloading a nominal variable like total population or per capita income with get geometry using get_acs() or simply using the tigris method, as covered in previous section & then implementing a merge. We have illustrated both methods below.
tractDf <- get_acs(geography = 'tract', variables = c(totPop18 = "B01001_001",
hispanic ="B03003_003",
notHispanic = "B03003_002",
white = "B02001_002",
afrAm = "B02001_003",
asian = "B02001_005"),
year = 2018, state = 'IL', geometry = FALSE) %>%
select(GEOID, NAME, variable, estimate) %>%
spread(variable, estimate) %>%
mutate(hispPr18 = hispanic/totPop18, WhitePr18 = white/totPop18,
AfrAmPr18 = afrAm/totPop18, AsianPr18 = asian/totPop18) %>%
select(GEOID,totPop18,hispPr18,WhitePr18,AfrAmPr18, AsianPr18)
tractShp <- get_acs(geography = 'tract', variables = c(perCapitaIncome = "DP03_0088"),
year = 2018, state = 'IL', geometry = TRUE) %>%
select(GEOID, NAME, variable, estimate) %>%
spread(variable, estimate)
tractsShp <- merge(tractShp, tractDf, by.x = 'GEOID', by.y = 'GEOID', all.x = TRUE)
head(tractShp)## Simple feature collection with 6 features and 3 fields
## geometry type: MULTIPOLYGON
## dimension: XY
## bbox: xmin: -88.79336 ymin: 41.7943 xmax: -87.63536 ymax: 41.95088
## CRS: 4269
## GEOID NAME perCapitaIncome
## 1 17031843800 Census Tract 8438, Cook County, Illinois 19331
## 2 17037001002 Census Tract 10.02, DeKalb County, Illinois 11308
## 3 17031243000 Census Tract 2430, Cook County, Illinois 48843
## 4 17031250600 Census Tract 2506, Cook County, Illinois 22905
## 5 17031251700 Census Tract 2517, Cook County, Illinois 14739
## 6 17031260400 Census Tract 2604, Cook County, Illinois 12610
## geometry
## 1 MULTIPOLYGON (((-87.64554 4...
## 2 MULTIPOLYGON (((-88.79317 4...
## 3 MULTIPOLYGON (((-87.68195 4...
## 4 MULTIPOLYGON (((-87.7756 41...
## 5 MULTIPOLYGON (((-87.74826 4...
## 6 MULTIPOLYGON (((-87.74061 4...
zipChicagoShp <- get_acs(geography = 'zcta', variables = c(totPop18 = "B01001_001",
perCapInc = "DP03_0088"),
year = 2018, geometry = TRUE) %>%
select(GEOID, NAME, variable, estimate) %>%
spread(variable, estimate) %>%
rename(totPop18 = B01001_001, perCapitaInc = DP03_0088) %>%
filter(str_detect(GEOID,"^606")) %>%
select(GEOID,totPop18,perCapitaInc)
head(zipChicagoShp)## Simple feature collection with 6 features and 3 fields
## geometry type: MULTIPOLYGON
## dimension: XY
## bbox: xmin: -87.64138 ymin: 41.85206 xmax: -87.60586 ymax: 41.88908
## CRS: 4269
## # A tibble: 6 x 4
## GEOID totPop18 perCapitaInc geometry
## <chr> <dbl> <dbl> <MULTIPOLYGON [°]>
## 1 60601 14675 92125 (((-87.63396 41.88698, -87.63102 41.88751, -87.628 41.88751, -87.62524 …
## 2 60602 1244 100507 (((-87.63389 41.88447, -87.62536 41.8845, -87.6243 41.88212, -87.62765 …
## 3 60603 1174 117992 (((-87.63382 41.88195, -87.62781 41.88204, -87.62765 41.88077, -87.6243…
## 4 60604 782 114575 (((-87.63375 41.87939, -87.62428 41.87955, -87.62298 41.8783, -87.62299…
## 5 60605 27519 83408 (((-87.63311 41.87686, -87.62421 41.877, -87.62299 41.8759, -87.62298 4…
## 6 60606 3101 132765 (((-87.63998 41.88851, -87.63936 41.88908, -87.63871 41.88724, -87.6376…
5.6 Save Data
We previously saved our files as CSVs. Now let’s save the final shapefile of ZCTA scale data for future use, using write_sf.
## Warning in abbreviate_shapefile_names(obj): Field names abbreviated for ESRI Shapefile driver
5.7 Appendix
5.7.1 Explore variables
Using tidycensus we can download datasets from various types of tables. The ones most commonly used are:
- Data Profiles - These are the most commonly used collection of variables grouped by category, e.g. Social (DP02), Economic (DP03), Housing (DP04), Demographic (DP05)
- Subject Profiles - These generally have more detailed information variables (than DP) grouped by category, e.g. Age & Sex (S0101), Disability Characteristics (S1810)
- The package also allows access to a suite of B & C tables.
We can explore all the variables for our year of interest by running the code below. Please note as the Profiles evolve, variable IDs might change from year to year.
sVarnames <- load_variables(2018, "acs5/subject", cache = TRUE)
pVarnames <- load_variables(2018, "acs5/profile", cache = TRUE)
otherVarnames <- load_variables(2018, "acs5", cache = TRUE)
head(pVarnames)## # A tibble: 6 x 3
## name label concept
## <chr> <chr> <chr>
## 1 DP02_00… Estimate!!HOUSEHOLDS BY TYPE!!Total households SELECTED SOCIAL CHARACTERISTICS…
## 2 DP02_00… Percent Estimate!!HOUSEHOLDS BY TYPE!!Total households SELECTED SOCIAL CHARACTERISTICS…
## 3 DP02_00… Estimate!!HOUSEHOLDS BY TYPE!!Total households!!Family ho… SELECTED SOCIAL CHARACTERISTICS…
## 4 DP02_00… Percent Estimate!!HOUSEHOLDS BY TYPE!!Total households!!F… SELECTED SOCIAL CHARACTERISTICS…
## 5 DP02_00… Estimate!!HOUSEHOLDS BY TYPE!!Total households!!Family ho… SELECTED SOCIAL CHARACTERISTICS…
## 6 DP02_00… Percent Estimate!!HOUSEHOLDS BY TYPE!!Total households!!F… SELECTED SOCIAL CHARACTERISTICS…
A tibble with table & variable information has three columns : name, label, concept.
Name is a combination of table id and variable id within that table. Concept generally identifies the table name or grouping used to arrange variables. Label provides textual details about the variable.
We can explore these tibbles to identify the correct variable ID name to use with the get_acs() function by using View(sVarnames) or other filters e.g. for age
sVarnames %>% filter(str_detect(concept, "AGE AND SEX")) %>% # search for this concept
filter(str_detect(label, "Under 5 years")) %>% # search for variables
mutate(label = sub('^Estimate!!', '', label)) %>% # remove unnecessary text
select(variableId = name, label) # drop unnecessary columns and rename## # A tibble: 6 x 2
## variableId label
## <chr> <chr>
## 1 S0101_C01_002 Total!!Total population!!AGE!!Under 5 years
## 2 S0101_C02_002 Percent!!Total population!!AGE!!Under 5 years
## 3 S0101_C03_002 Male!!Total population!!AGE!!Under 5 years
## 4 S0101_C04_002 Percent Male!!Total population!!AGE!!Under 5 years
## 5 S0101_C05_002 Female!!Total population!!AGE!!Under 5 years
## 6 S0101_C06_002 Percent Female!!Total population!!AGE!!Under 5 years
sVarnames %>% filter(str_sub(name, 1, 5) == "S0101") %>% # search for these tables
filter(str_detect(label, "Under 5 years")) %>% # search for variables
mutate(label = sub('^Estimate!!', '', label)) %>% # remove unnecessary text
select(variableId = name, label) # drop unnecessary columns and rename## # A tibble: 6 x 2
## variableId label
## <chr> <chr>
## 1 S0101_C01_002 Total!!Total population!!AGE!!Under 5 years
## 2 S0101_C02_002 Percent!!Total population!!AGE!!Under 5 years
## 3 S0101_C03_002 Male!!Total population!!AGE!!Under 5 years
## 4 S0101_C04_002 Percent Male!!Total population!!AGE!!Under 5 years
## 5 S0101_C05_002 Female!!Total population!!AGE!!Under 5 years
## 6 S0101_C06_002 Percent Female!!Total population!!AGE!!Under 5 years
e.g per capita income, we can check on DP table variables.
pVarnames %>% filter(str_detect(label, "Per capita")) %>% # search for variables
mutate(label = sub('^Estimate!!', '', label)) %>% # remove unnecessary text
select(variable = name, label) # drop unnecessary columns and rename## # A tibble: 2 x 2
## variable label
## <chr> <chr>
## 1 DP03_0088 INCOME AND BENEFITS (IN 2018 INFLATION-ADJUSTED DOLLARS)!!Per capita income (dollars)
## 2 DP03_0088P Percent Estimate!!INCOME AND BENEFITS (IN 2018 INFLATION-ADJUSTED DOLLARS)!!Per capita i…
pVarnames %>% filter(str_detect(label, "Under 5 years")) %>% # search for variables
mutate(label = sub('^Estimate!!', '', label)) %>% # remove unnecessary text
select(variable = name, label) # drop unnecessary columns and rename## # A tibble: 2 x 2
## variable label
## <chr> <chr>
## 1 DP05_0005 SEX AND AGE!!Total population!!Under 5 years
## 2 DP05_0005P Percent Estimate!!SEX AND AGE!!Total population!!Under 5 years
The order and structure of profile tables can change from year to year, hence the variable Id or label, so when downloading same dataset over different years we recommend using the standard B & C tables.
otherVarnames %>% filter(str_detect(label, "Per capita")) %>% # search for variables
mutate(label = sub('^Estimate!!', '', label)) %>% # remove unnecessary text
select(variable = name, label) # drop unnecessary columns and rename## # A tibble: 10 x 2
## variable label
## <chr> <chr>
## 1 B19301_001 Per capita income in the past 12 months (in 2018 inflation-adjusted dollars)
## 2 B19301A_001 Per capita income in the past 12 months (in 2018 inflation-adjusted dollars)
## 3 B19301B_001 Per capita income in the past 12 months (in 2018 inflation-adjusted dollars)
## 4 B19301C_001 Per capita income in the past 12 months (in 2018 inflation-adjusted dollars)
## 5 B19301D_001 Per capita income in the past 12 months (in 2018 inflation-adjusted dollars)
## 6 B19301E_001 Per capita income in the past 12 months (in 2018 inflation-adjusted dollars)
## 7 B19301F_001 Per capita income in the past 12 months (in 2018 inflation-adjusted dollars)
## 8 B19301G_001 Per capita income in the past 12 months (in 2018 inflation-adjusted dollars)
## 9 B19301H_001 Per capita income in the past 12 months (in 2018 inflation-adjusted dollars)
## 10 B19301I_001 Per capita income in the past 12 months (in 2018 inflation-adjusted dollars)