How much money do the makers of Simpsons make annualy?

It seems that the Simpsons can generate a lot of money for Fox. It is estimated that it can make 1 billion dollars a year. This was back in 2003 though. There are a lot of other animated shows available and there are also a lot of viewers who have already succumbed to old age but the fact still remains that there are a lot of merchandise and other items that will allow this cartoon and the various characters to become a hit among different people coming from various parts of the world. Take note that there are still other costs that are involved such as the marketing and the promotion of the show.