Both Gates increased his wealth this year to $54 billion and Buffet's stack reached $45 billion. Most of the billionaires on the list released Tuesday grew richer -- their collective net worth was up 8 percent to a total of $1.57 trillion.
The super-rich got dinged by the economic slump but recovered during the past year.
Larry Ellison, head of Oracle, was in third place with $27 billion, followed by Christy Walton, a daughter of Walmart founder Sam Walton, with $24 billion. Brothers Charles and David Koch followed with $21.5 billion each.
The rest of the top 10 included three more Waltons, Jim, Alice and S. Robson, and New York Mayor Michael Bloomberg, with $18 billion.
Mark Zuckerberg, founder of Facebook, was only in 35th place. But the 245 percent increase in his wealth outpaced the growth experienced by everyone else on the list.
Zuckerberg lost his claim to be the youngest person on the list to another Facebook billionaire, Eduardo Saverin, 26, who is eight days younger.
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