freq  rolling       err rolling
1     0.078874827   0.0099655825
2     0.07253767    0.013797716
5     0.059269324   0.014006739
10    0.05402621    0.012924176
12    0.052176972   0.0078535426
15    0.05082724    0.011346665
18    0.056573041   0.01099597
20    0.05948949    0.011480505
30    0.053605688   0.010873141
50    0.052091079   0.0093300957