or even just within the Big12 footprint there are some very big bumps (e.g. UH 25%+, TCU 30%+, UVA ~15%, Ga Tech ~12%, UConn 20%+, UCF ~10%, etc.) that would raise some eyebrows. My belief is that most people west of the rockies have no idea the spread of fans and influence that BYU has and can generate. This can add up to big dollars for the coffers of the lesser B12 teams.
I think it would be reasonable to exclude teams in the west given the large BYU & LDS populations there are and already known about.
The 70% number you had for percentage of non-Utah residents that attend BYU can be very shocking to people outside of Utah. I don't think there are very many people nationally that truly understand the national reach that BYU has.
By the way - great work!!