content: I agree with you. Not sure about other countries, but according to Wiki about South Korea, "According to the census of the year 2005, 22.8% of the population identifies as Buddhist, 18.3% as Protestant and 10.9% as Roman Catholic, totaling a 29.2% Christian population."   So basically Christianity makes up almost 60% of population of South Korea. But in the map, it's almost grey.