To be honest, it isn't really fair to evaluate teachers based on student test scores. Students in some mostly white upstate district are going to score higher than a 98% black district like parts of the Bronx, that's just a fact.
“I am not one of those weak-spirited, sappy Americans who want to be liked by all the people around them. I don’t care if people hate my guts; I assume most of them do. The important question is whether they are in a position to do anything about it. My affections, being concentrated over a few people, are not spread all over Hell in a vile attempt to placate sulky, worthless shits.” - William S Burroughs