The answer is that anything less than 100% of blacks being physicists automatically means that "percentage-wise" there are fewer black physicists than black Americans. And, since there are literally thousands of fields of endeavor, it stands to reason that percentage-wise, there are dramatically fewer black physicists than black Americans.
This idiot does not even know how to properly formulate the question he wants answered.
According to the Jewish Virtual Library, since the Nobel was first awarded in 1901 approximately 193 of the 855 honorees have been Jewish (22%). Jews make up less than 0.2% of the global population.
If you want to succeed like them, do what they do!
This is something the left absolutely rejects.