Andy,
The problem is that most schools claim that theirs are the best. Or at least better than most of the others. It is one of those rather strange situations where everyone is well above average!!!!!!
The results that you saw on my notice board are straight from the CAA e-mail. I make no changes other than to delete the student names. I do this to avoid embarassing the small number of students who do badly.
You may have noticed that I also publish the national averages, so that students can judge for themselves where we stand.
But each school receives only its own results, plus the averages for the entire CAA realm. So no school can truly say that they know that theirs are the highest.