Sign it "Elmer Fudd" ...
Seriously, anyone who would put this in an agreement is just enough of a moron to chase you down. It only costs about $60 bucks to file a lawsuit and you end up paying a bunch to get it tossed.
Make 'em take it out. If they won't, have them sign one that guarantees you X number of students...and pick a nice fat number...and says any decline in students that costs you money, they will pay the difference.
Then stand back as they choke.