And don't forget about NAIA.
You could look at each team's roster on their web site, and do a head count of Ohio kids in each graduating class. There are 11 DI programs in Ohio, but I've never counted the other divisions. There were 2 Ohio kids in my DD's senior class, 2 Juniors, 1 sophomore, and 1 freshman.
With 18 on the roster this year, that's 11%