"How many students have left your class for another class or another school because parents felt your teaching was in some way inadequate?"
Almost none, but it's because I'm the "good" teacher. I do however have a couple of students per year that transfer from other high schools in my district to my school in order to have me as their computer science teacher instead of one of the other five CS teachers in our district.
I very occasionally lose a kid (one every few years) for my video game programming course because there's another CS teacher in my district that's clearly better at teaching that course than I am.
Were you not aware that students can sometimes transfer within high schools in a school district?
Edit: Oh! Also I teach computer science full time. The teachers at the other high schools have fewer students in their programs than I do (even though our schools have approximately the same number of students overall), so they have to pick up extra courses to fill out their schedules (like babysitting the in-school suspension kids) whereas I get to only teach CS.
If you feel that your position is in no way different from tokenadult's, how many students have left your class for another class or another school because parents felt your teaching was in some way inadequate?