In previous releases, the ratio was 1: 4
So when the editor is a 1, then created the game 4 new regens from that country / region.
Whether that is still the case in the current PCM, I do not know.
To be honest I don't know if there's a certain formula regulating the amount of riders that a certain region produces, in PCM 15. Definitely it's not 4:1 ratio anymore, because I think that the regions with the lesser amount of riders in OfficialRelease had 3, and as much as Cyanide can be weird in your eyes, I doubt they'd make Hong Kong produce 12 youngsters.
It's probably along the lines of 1:3/1:2 or even 1/4 now, instead of 4:1 as Lof said. Will run some tests and update my post.
UPDATE: So in the Expansion Pack 1.6 there are 114 riders from Colombia. The weight of that very same region is 50 in the DB. How many more riders there will be in my save compared to before after I start career? Well, with Colombia, I only had 8 more, 122.
Let's see if this applies to some other regions. Let's try with Vlaanderen for instance. In the DB there are a whopping 268 riders from there. In the db, that region's weight is 55. If the same formula applies to this one, we should have 8.8 riders more, which rounds up to 9. And in fact, they turned out to be 277 in the end.
But we're still not sure about it, right? Let's see if the same applies to Great Britain. In the DB there are exactly 140 riders from there. The weight is 40 so I should have 6,4, that rounds down to 6. In this case I found 7 riders more though, which either means that the game always rounds up the result or that I shouldn't have based myself only off Colombia for the remaining regions.
So as a result, we can say that the formula that the game uses to calculate the amount of regens is (weight)/~5,5.
Edited by matt17br on 07-12-2015 17:19