The youngest self-made woman on the FORBES Billionaires list on how she earned her riches.

NEW YORK - Mexican tycoon Carlos Slim retained his position atop Forbes magazine's annual list of the world's billionaires on Wednesday with an estimated worth of $69 billion, while his Mexican rival Ricardo Salinas Pliego enjoyed the largest increase in wealth.

Microsoft Corp cofounder Bill Gates ranked second at $61 billion and Warren Buffett third at $44 billion. France's Bernard Arnault, the richest person in Europe, repeated at No. 4. They were the same top four as last year.

The youngest self-made woman at age 41 was Spanx founder Sara Blakely, whose net worth of $1 billion from her business of making slimming undergarments affirmed there was profit in vanity. Blakely, ranking at No. 1,153, was among 104 women on the list.

Fifty-eight countries were represented on the list of a record 1,226 billionaires whose average fortune was $3.7 billion. Some 128 billionaires were new to the Forbes rankings this year, including Colombia's Alejandro Santo Domingo, 35, the richest new billionaire in the world ($9.5 billion) and the face of Santo Domingo Group after last year's death of his father.

In addition to the usual aging plutocrats and heirs, Facebook founder and CEO Mark Zuckerberg, 27, ranked 35th with a net worth of $17.5 billion. The social media heavyweight announced plans last month .