NEW YORK, March 21(Xinhua) -- U.S. President Donald Trump slipped 220 spots on Forbes 2017 Billionaires List while Bill Gates topped the list for the forth straight year according to the list released on Monday.

Trump has lost 1 billion U.S. dollars, with his worth dropping from 4.5 billion dollars to 3.5 billion dollars. That was enough to see the president fall from the 324th to 554th spot on the list. Forbes pinned his wealth shrinkage on the receding real estate market. Forty percent of Trump's wealth is tied up in Trump Tower and eight other buildings within a short distance of it.

"Midtown Manhattan real estate is down; therefore, so is Donald Trump's fortune," Forbes said.

Trump took issue with Forbes' data in the past, saying it disregards his brand value. In his presidential campaign, Trump acclaimed that he was worth 8.7 billion dollars, then "in excess" of 10 billion dollars in a personal financial disclosure form.

"We do not give any credit for 'brand value' to Trump or Oprah or any other person on our list," Forbes editor Randall Lane told the Washington Post. "We feel a person's brand value is already reflected in income and value of the deals they cut."

Bill Gates still ranked the richest person in the world with an estimated fortune of 86 billion dollars. He was followed by Warrant Buffet, the chief of Berkshire Hathaway, whose wealth is around 75.6 billion dollars.

Amazon founder Jeff Bezos came third, followed by Amancio Ortega from Spanish clothing retailer Zara. Facebook creator Mark Zuckerberg came fifth.

The global billionaire population climbed nearly 13 percent from 1810 to 2043 over the past year. This annual increase is at an all-time high in the 31-year history of the list, Forbes said. The United States had the most billionaires with a number of 565, and China came the second with 319 billionaires.