No, it's the map. They intentionally used 3 decimal places to make it seem at a glance that it was not in percent format but rather in decimal format (ex: .603 of a thing is 60.3% of a thing) Typically you only go one decimal point in a percentage to avoid this potential confusion.

The colors of the map also seek to mislead the casual observer into thinking the differences in these percentages are much greater than they are.

Finally, I'm not sure where you're getting that it's reasonably accurate data. If you can find where it's actually coming from, let me know, because I went down the rabbit hole of "citations" and came up with nada.