Probably 100 people at the interview. Historically they hire 70% or so I'd venture to guess. It's an easy interview in comparison to many. MAke sure your stuff is in order and there used to be an ATP written type of deal. Don't know if there still is. You'll be interviewed vy 2 line pilots most likely. Good cop bad cop situation.
There's a new HR guy, who so far seems pretty on the ball, so all info is subject to change.