Growth rate question

I have a normal female ball python that I bought March of 06 that was probably a very late 05. She eats very good for me never refuses a meal and has only slowed down on eating in the winter to one med rat every 2 weeks and she only weighs around 1250 grams now. My question is how do people have 08s that already weigh 900+ grams?

I have 07's around 700g and 08's are all at close to 300g.... Not quite sure if the numbers add up.... :confused:

Ok thanks the person with 08s that are 900+ grams must have misput what year or somethin.