Trudy, generally, a couple "big name" hybridizers I know try to select 10% each year.
So, if they have 10,000 seedlings bloom, they will select 1000. The next year, they will select 100 from that 1000. Then the next year, 10 from that 100. So, in the end, 10 from 10,000.
But, then, Jim Biaglow, who has passed on now, would select 10 from 50 and then 2-3 to intro from that. He had some nice plants! RAPTOR being one of them. He was disabled, in a wheel chair and could not do large numbers of seedlings. So, he was very, very careful what crosses he made, and only grew a few hundred seed a year.
