Well that is probably because you're a girl... no offense. I was watching some chick at Progression, and there was too much inhibition to go out of the comfort zones, even among decent skiers; seems like a girl thing.
But as for the main question.. don't set yourself a quota, because the way you asked it seems like it will set yourself up for disappointment.
Several things will certainly influence your progression (as others have said)
-days skiing
-background in skiing (are you solid as fuck or still sketchy)
-where you ride
-you (like, are you willing to get some bruises? can you apply your mind or something like that? do you have natural air sense, luck, etc etc)
-agility
-who you ride with
-blah blah blah
work on fundamentals, like solid spins, solid landings, solid grabs, solid everything, and add shit as you go along. I see a ton of people like start trying switch corks (or what have you) and shit because they are starting to get some solid 360s in. fucking whack.