According to this article by Kim Masters on the Daily Beast: "Since 1984, Spielberg has collected 2 percent of the money from all Universal theme parks outside Southern California—Orlando, Japan, Hong Kong, etc. An executive familiar with the terms says this is a “humongous deal” for Spielberg, who is very involved with the parks and visits them and provides his notes on the attractions. The deal also includes a provision allowing Spielberg to demand that Universal buy him out altogether—meaning that Universal would have to cough up hundreds of millions of dollars."
Just think about that for a moment...
Two per cent.
Of all money taken.