[Drolefille]

It isn't usually finalized before then. You have an estimate because you know how many PNMs are left, but there's no way to know how many will be left by Pref night for certain. Based on aopirose's example, estimated quota would have started at 25 (150/6) and worked its way down to 17 as girls dropped out or were completely cut.

You can look at statistics for previous years and guess but it's never certain.