Out of those 50, just 11 were drafted. (Some in 2016 class aren't done with college yet).
— Sam McKewon (@swmckewonOWH) May 5, 2020
The average draft round of said QBs, by years:
2012: 7.1
2013: 7.4
2014: 6.8
2015: 5.9
2016: 6.9 (some aren't in NFL yet)
So, outside of 2015, the average is a free agent signing.