Mayor Michael Bloomberg has moved up a few notches on Forbes annual billionaires list.

The mayor jumped seven spots to number 13, with a net worth of $27 billion.

Number one on the list of the world's richest people remains Carlos Slim.

The telecom magnate from Mexico has a net worth of $73 billion.

Bill Gates keeps the number two spot with $67 billion.

The biggest gainer on the list is Amancio Ortega, who founded the Spanish retailer Zara.

He added almost $20 billion to his net worth, bringing his total to $57 billion and knocking Berkshire Hathaway Chairman and CEO Warren Buffett out of the top three for the first time since 2000.