I'll take a stab
These numbers are certainly unofficial, and I have no idea how accurate they are, but perhaps they can shed some light on the question of how many folks are still in the pool. Back in Feb the System Chief Pilot circulated a list with 70 names on it who were either in the pool or to be called for an interview. Best case, all made the cut and were still waiting for the call for a class date. Number in pool = 70.
Since then we have hired 12 internals (were not on the list) and 28 who were on the list. Pool now equals 42 max. 16 are slated to start classes this month, pool will equal 26 max at the end of June. I don't think I've missed any classes, and I marked off the names from the master seniority list which includes folks in training, so I think my numbers are pretty good. What I don't know (and have no way of finding out) is how many folks on the list who were to be interviewed actually passed or how many folks on the list who were in the pool have actually gone to work for somebody else. That would make the number smaller of course.
There have been a small number of interviews over the past month or so as well so there could be some more people entering the pool since the original email from the SCP, so the number could also have gone up from new folks passing the interview.
Again, this is just an unofficial calculation from the little bit of info that trickles down to the line. I hope it is helpful and somewhat accurate.
Best of luck.
FJ