How big is the pool? Some July poolies (maybe half?) already have class dates, and if they held interview groups of 18 applicants twice a month running through the first week of October, it would maybe look like this:

July - 18
Aug - 36
Sep - 36
Oct - 18
_________
Total - 108

This is making a lot of assumptions of course, including the number of interviews held and a 100 percent hire rate (which has been normal) and nobody leaving the pool for other airlines...