I use the USNWR numbers for interviewed/accepted/matriculated to try and get a read; if a school admits like 70% of interviewees then I assume the waitlist has to be moving especially if far fewer matriculate. I think it is safe to assume that admitting three people per seat right off the bat would be a bit daring given how particular school's are with class size. Of course, using "assume" every sentence means exactly what it looks like. My .02.