So, I went back to the past years of the AC rankings and got some numbers for the deepest class (having the most ranked) and the number of #1 ranked kids. This is what i got.

2007-2008
321a – 11 ranked wrestlers – 10%
0 #1 ranked wrestlers
4a – 35 ranked wrestlers – 31%
3 #1 ranked wrestlers
5a – 32 ranked wrestlers – 28%
9 #1 ranked wrestlers
6a – 36 ranked wrestler – 32%
2 #1 ranked wrestlers

2008-2009
321A – 24 ranked wrestlers – 17%
0 #1 ranked wrestlers
4A – 46 ranked wrestlers – 32%
5 #1 ranked wrestlers
5A – 39 ranked wrestlers – 27%
3 #1 ranked wrestlers
6A – 35 ranked wrestlers – 24%
6 #1 ranked wrestlers

2009-2010
321A – 23 ranked wrestlers – 16%
0 #1 ranked wrestlers
4A – 44 ranked wrestlers – 31%
9 # 1 ranked wrestlers
5A – 36 ranked wrestlers – 25%
2 #1 ranked wrestlers
6A – 39 ranked wrestlers – 28%
3 #1 ranked wrestlers

2010-2011
(as of 2/14)
321a – 27 ranked wrestlers – 18%
1 #1 ranked wrestler
4a – 46 ranked wrestlers – 32%
3 #1 ranked wrestlers
5a – 39 ranked wrestlers – 27%
7 #1 ranked wrestlers
6a – 34 ranked wrestlers – 23%
3# 1 ranked wrestlers

Out of the 4 classes 4a normally has the deepest. The first year the AC rankings came out was the only year they didn't have the deepest class. The bigger classes have most of the top guys through out the years except for the 2010 season.