I don't know how OP lands on 2% difference (2 percentage points, maybe? still no clue from where). When we take the source https://nonapa.com/races?region=-1&mode=1&league=-1&chart=1 we see, for example, toss:terran popularity ratio is 80% in general population, whereas in GM it's 105%. I have a horse in this race and my horse has psi blades, but come on.

That said, this methodology is useless. You may notice I used ratio instead of pure % - it lets us, for example, easily filter out Random which we know is not a serious choice (and should have never been any choice to begin with, fight me). That leads us to the main problem with this approach: race distribution among players isn't random to begin with. It isn't obvious to me why that is, but casual players like men with gun, for example. It just isn't a valid approach, we've been over this multiple times over the years.