The cohorts aren't defined by race though, or even ethnicity, are they? Someone born in china, raised in Brazil who did their undergrad in France and got their

The cohorts aren't defined by race though, or even ethnicity, are they? Someone born in china, raised in Brazil who did their undergrad in France and got their doctorate in India before publishing a fraudulent paper as a postdoc at UCSF is going to be counted agains the US, right? On another front though, what's the margin of error on the sample sizes used in the paper?