Busch Gardens Williamsburg was the only one of the Top 20 amusement parks in North America to suffer a drop in attendance last year, according to a report from the Themed Entertainment Association. Water Country USA also fared worse than in 2010.

Busch Gardens execs attribute the slippage largely to rain. Attendance fell by 56,000 to 2.744 million, or 2%. All the other Top 20 parks showed at least modest gains, and the industry as a whole was up 2.9%, according to the report

http://www.vagazette.com/articles/2012/07/21/news/doc5009df0eb99e8619129146.txt

Is there a link to the top 20 least visited parks?

Whoops sorry. Didn't see the link

That isn't the top 20 least visited parks. Then again, I doubt that's what you meant.