Even if you were correct, when was the last time a non-African born set a running (or sprinting, lol) record? In this millenium, I remember only a certain lady with extremely suspicious blood values, during the EPO era.
But in fact, the drug cheats numbers were 43.6% at World's (some 1800 athletes) and 57.1% at PAN - not such a huge difference. Both likely underestimated, according to the authors.
And based on both suspicious blood values, and athletes caught, the Africans are somewhere in the middle, far ahead of us, way behind the Russians.
From the Sunday Times 2015 leak, we have a list of blood-doping suspects by country. There, the "leaders" were Russia, Ukraine, Turkey, Greece, Morocco and Bulgaria, with a percentage from 30 - 22%; twice as high as Kenya's 11%, which was on par with the EU countries Holland and Spain. Overall average was 15%. For comparison, UK and USA had 4% and 5%, respectively.
And again, one has to dope quite brutally to crash through the generous borders of the ABP. E.g., Ashenden showed that one can safely increase Hct by 10 - 15%, and Poistogova for example never got flagged despite her hard-core EPO usage. That implies that the real percentages are substantially higher than for example the 30% for Russia, 11% for Kenya, or 5% for USA.
Plus, that list neither includes HGH nor testo nor certain peptides.