they try and keep them around 60, as there are only 60 seats in a classroom. more then 60 (we did for a bit) and you get people sitting in the isles and thats technically a fire hazard so they prefer not to.
we started with 60, then droped to 50 within 2 weeks, then got some from pat and wft and were upto 60 again, now in week 5 were down to 56 and this is VR week so we may loose a few more.