What are the percentages of whites and blacks in the total population of North America? ~~ Urgent request~~

It is difficult to count, and statistics are subject to accuracy and error. To count a state, only the statistical data of all countries in the state are needed, and the population is mobile, and statistics at any point in time are timely. If you only need a divisor, this seems not easy to obtain. Let me put it this way, if the black population in country a is 2% to 3%, and the total population is 10 million plus or minus 100,000 (I will give 100,000 floating population Your calculation is very, very low.), country b is 3% to 4%, the population is 20 million plus or minus 150,000, and there are countries such as cdef, 20 countries have already led to a very interesting result. The total number of 20 fruits is a very wide range, and such statistics are equivalent to no statistics.