Guest -

Difficult to do, but not so hard to get close. All you have to do is "dumb down" all the good students so that the average drops within easy reach of nearly all. Then (as some school systems in the US do) you define "special categories" for the ESL and otherwise "learning disadvantaged" ones to make the ones who would otherwise appear as below average "disappear" from the records.

Sort of like the Nazis did - solve the unemployment problem by sending anyone without a job to a labor camp.

Note: Not calling anyone a Nazi. Just pointing out that sometimes bizarre accounting and manipulating of the statistics solves political problems.

John