Are you asking for the figures for the whole thing including the parks, citywalk, the parking structure, the hotels, and the little remaining unused land or just the parks themselves?
I actually don't know the answer to the whole thing but if you ask this question over on ioacentral.com someone there may very well know. There's a couple of people who know information like that over there.
Universal Orlando® Resort An 840-acre complex housing Universal Studios Florida, Universal's Islands of Adventure, Universal CityWalk and film and television production facilities.