President Trump’s fortune has dropped by roughly $1 billion since last year, according to Forbes magazine’s latest ranking of the world’s billionaires.

The decline in Trump’s net worth is due to a drop in the value of office space in Midtown Manhattan, according to the Guardian. Forbes ranks Trump as the world’s 544th richest person, after coming in at No. 324 last year. He has famously refused to reveal his tax returns that would identify his actual net worth, but has claimed it’s “in excess” of $10 billion.

Bill Gates once again sits atop the list. The Microsoft co-founder has now been the richest person in the world for 18 out of the past 23 years, per Forbes.. He has a fortune of $86 billion, up from $75 billion last year, while Warren Buffett ranks No. 2 with $75.6 billion. Amazon’s Jeff Bezos is third with $72.8 billion, followed by Spanish clothing retailer Amancio Ortega and Facebook’s Mark Zuckerberg.

Also Read: Stephen Hawking on Potential Second Trump Term: 'God Forbid' (Video)

Trump might have slipped, but other members of the list are doing quite well for themselves. Forbes’ tally includes 2,043 billionaires, up from 1,810 in 2016, with an average net worth of $3.75 billion. The total combined net worth of this year’s billionaires is $7.67 trillion, up from $6.48 trillion last year.

“Booming stock markets, higher commodities prices and plain old-fashioned entrepreneurship helped make this a record year in terms of wealth creation around the globe,” assistant managing editors of wealth at Forbes Media Luisa Kroll and Kerry Dolan said in a statement.

The total number of women on the list is 227, up from 202 in 2016. 56 of the billionaires are under 40 years-old, down from 66 in 2016.

Bezos, who has been producing award-winning content on Amazon’s streaming service, is the only person from the entertainment industry among the Top 20, which also features three different members of Wal-Mart’s Walton family and Las Vegas casino tycoon Sheldon Adelson.