My sister’s score went up that much. She was too stoned to take the test the first time and made a 480. I think the next score was in the 700’s.
I was failing geometry throughout 9th. grade but managed to multiple-guess my way to the highest mark in the class on the final exam. They investigated me for cheating. There was none. I passed with a “C” for the year.
Three years later I got accepted at a fairly elite college (but didn’t go because my dad thought it was too expensive).
So there is a chance this was just luck-of-the-draw.
Only half-way stoned the second time?
Nothing unusual about improving your score in nearly a year if you work at it... unless there is some other reason to think cheating was involved i’d Support the student too.