Often when you see recruiting breakdowns the bands widen as you go down the list, which makes sense to me. In other words a player ranked 5th is typically night and day over a player ranked 25th. However a player ranked 70 might not be much different than 100. So, you see that as you move down the bands widen. 1-10,11-25, 26-50, 51-75, 76-100....something like that.
I am embarrassed to say that I didn;t look closely enough at the chart you posted and didn't catch that every grouping but the last was for 5 players per class. Paterfamilias, you put a lot of thought, effort and data into your posts, and deserve better. Oh, well, probably not the first time someone jumped to conclusions because they didn't look closely enough. Please keep posting things like this, I find them very interesting.
Lol... Don't beat yourself up. I'm the one that did it and it took me an hour to find it and another half hour looking at the chart and the associated data to remember what the whole study was even about. At first glance, I didn't remember what the 45's were either.