How Many Amish Are There?

I'm not a big numbers geek, but I do enjoy a good chart of map, and I found some good ones on the Indiana University website.

As of the 2000 census, there were almost 20,000 Amish people in Indiana—third largest number in the United States, with Ohio and Pennsylvania almost tied for first.  The Indiana counties with the heaviest Amish population were Lagrange, Elkhart, Adams, and Daviess (in that order).  Lagrange County had almost 6,000 Amish—about 17% of the population of the county—which was a higher percentage of Amish than any other county in America.

This is old information, but still interesting..  Since the Amish generally double in population every 20 years, I wonder what the figures will look like in 2020?

The Amish in Indiana and the United States