check out my thread on NYCPD... 99% of kids handcuffed in 2016 were black/latino.The system in which a white teacher is more likely to view a black student as a threat, while identifying with the white student, and result in harsher punishments for the same kinds of misbehavior.
That's one example. It is not a 100% occurrence. There are too many other factors at work that means that it's practically impossible to quantify. But it exists, like the other prejudices in our world.
99%-Let that sink in.