Microsoft founder and philanthropist Bill Gates has reclaimed the title of worlds richest person in Forbes latest ranking of billionaires. The finance publication puts Gates net worth at $76 billion and says Microsoft stock has helped him unseat Mexicos Carlos Slim, who held the top slot for four consecutive years. But Slims reign was the exception, not the rule: Forbes has listed Bill Gates as the worlds richest man for 15 of the past 20 years. And while his stake in Microsoft makes up less than a third of his total fortune (Forbes says Steve Ballmer may soon pass Gates as the companys largest individual shareholder), the stock has shot upward on Wall Street over the past year and tacked several billion onto Gates net worth.