They aren’t. This graph is from TJ Altimore who spreads lies about realignment and higher ed data. He has a schtick to put Big 12 institutions down. That 31.7 figure doesn’t include NCAA tourney basketball credits for the Big 12 but does for the other 3 power conferences in that graph.
That guy proved to be a nut with an agenda early on. Discredited time and again
We should all feel comfortable ignoring his slanted content