How about 5 Classes? Hadn't really done a lot of research on it but this would be how each division would be broken down, ADM wise:
5A- 1506-+, about 74 schools
4A- 1505-1175, about 76 schools
3A- 1174-880, about 75 schools
2A- 879-647, about 73 schools
1A- 646-0, about 81 teams, some of those...