You have a great writing style. I think I caught one grammar mistake. I actually wasn't looking for it. "The number of blacks behaving in this manner is small compared to the decent respectful ones but still much larger than what I see with any other racial or ethnic group. "
The verb is should be changed to are.
Correct me if I'm wrong, but the verb "is" is correct. You would say, "The number is small", not "The number are small." "Blacks" is not the subject of the sentence. "Number" is the subject of the sentence. "Number" is singular and, therefore, the verb used is correct.