President Donald Trump's ranking in the Forbes list of wealthiest Americans has dropped, as the magazine said the value of some of his Manhattan real estate holdings has declined recently.

Forbes ranked Trump, the first U.S. president to come solely from the private sector, as the 248th wealthiest person in America and put his wealth at $3.1 billion. He shares the spot with 27-year-old Snap co-founder and CEO Evan Spiegel, the youngest person on the list. The year before, Trump was ranked 156th and Forbes said he was worth $3.7 billion.

As a candidate, Trump said his net worth was more than $10 billion, but Forbes pegged that figure at $4.5 billion in September 2015. By Forbes' estimates, Trump's wealth has fallen 31 percent in two years.

Forbes attributed Trump's decline to a weakening New York retail and office real estate market, and new information about his assets. The Manhattan tycoon ranked 156 in 2016, the year he was elected to the White House.

Forbes said those on its 36th annual list of the 400 wealthiest Americans have a record-breaking, combined total net worth of $2.7 trillion, up from $2.4 trillion in 2016. Entrance to the exclusive club cost a record breaking $2 billion.v

The list is once again topped by Microsoft co-founder Bill Gates with a net worth of $89 billion, followed by Amazon's Jeff Bezos and Berkshire Hathaway's Warren Buffett.

There were 22 newcomers, including Netflix cofounder and CEO Reed Hastings. 26 people dropped off from last year, including U.S. Commerce Secretary Wilbur Ross.

There were only 50 women on the list. Alice Walton, the daughter of Wal-Mart founder Sam Walton, was the highest ranked at 13. Unlike her brothers, she has focused on curating art rather than working for Wal-Mart.

The biggest gainer in dollar terms was Facebook's Mark Zuckerberg, chalking up a $15.5 billion increase in net worth to retain his number four ranking at $71 billion.