I wouldn't go to such a precise number, but you are right that the majority do not end up testing positive. The test quantities are limited, so they try to sele

I wouldn't go to such a precise number, but you are right that the majority do not end up testing positive. The test quantities are limited, so they try to select candidates that are likely to have it. Even among these, the rate of positive tests seems to have ranged from ~5% up to ~20%.