I don't have exact stats, but...
Back in the day, about 180-200 women showed up for formal recruitment. (Actually, all 450 or so incoming freshman women were considered "registered" initially, so every year we had to justify why less than half of them were invited back to round 2!) Quota was usually around 30, with AEPhi getting a "special" quota of around half that (we wanted to remain a bit smaller). There were usually only 2-3 women who attended through pref and then didn't match. The rest dropped out after being disappointed by their round 2 or pref invites.
Now, my school has gone to deferred recruitment, and numbers are lower. I'm not sure how many registered or dropped out, but quota was (I think) 26 this year and 21 last year (

)
They don't understand the concept of a snap bid at my school.
There are 5 NPC sororities participating in FR.