Racism lives on not due to a lack of knowledge at an academic level racism is very well understood. White people like you, ask for proof in truth, not because you want to the truth, but because you want the the argument to stay stuck on some point so that you don't have to take what the other person says seriously.
"No it's not 15%...it's actually 13%" some stupid sh*t like that.
It also puts you in a position of power because then the person has to prove it to you, and then you can reject all forms of proof which was your goal in the first place.