The way I remember it is each aa was the same exp as level 51. Later eq live did some normalizations to make the first 100 or so aa's require less exp, with the curve increasing the more aa's you aquired, with I believe the amount of exp being equal with lvl 51 after some 1000 aa's or so....Something along those lines...Then they adjusted it again...
Not sure how accurate this info is but here goes..
https://forums.station.sony.com/eq/i...-it-work.2866/