I don't think there are hard-and-fast rules anymore, since they've done away with the 25-per-year cap they used to have. But the simple math would suggest five more per year (as total number of scholarships go from 85 to 105). So... ~30 per year?
Of course college football roster math is never simple. For instance when the new rules take effect, you'll be able to split scholarships in football, which you couldn't do before. I'd bet some of the guys who are currently PWOs get a partial scholarship, to keep them from going elsewhere for a full ride. And when you have two recruits you like roughly the same, maybe instead of telling them "first one to commit gets the spot," you just take both. Especially at positions where you rotate a lot and depth is super valuable like DL and WR.
Regardless, if the #1 RB in New Jersey wants in your class, I think you take him.