Donald Trump
Trump was hit by the cost of his presidential campaign as well we changes to Manhattan property valuesMark Wilson/Getty Images

Microsoft founder Bill Gates again tops Forbes' list of the world's richest people, in a year when the number of billionaires rose 13% to 2,043.

According to the magazine's annual rich list, Mr Gates' fortune rose to $86bn, from $75bn, followed by investor Warren Buffett, up $14.8bn to $75.6bn.

It was bad news for US President Donald Trump, who slipped 220 spots to 544 and must now rub along on just $3.5bn.

Forbes said the $1bn fall in his wealth was due to the slow US property market.

Meanwhile, on Sunday Trump's approval rating has sunk to 37 percent, while those who disapprove of the president's job stands at 58 percent, according to the latest Gallup poll. His approval rating stood at 45 percent one week prior.

Trump who primarily made his money through property investment is one of a handful of politicians to appear on the annual list.

The richest mainstream politicians are as follows:

10. Michael Bloomberg – $47.5bn – Former New York mayor

145. Mikhail Prokhorov –$8.9bn – Russian politician

199. Silvio Berlusconi – $7bn– Former Italian PM

367. Bidzina Ivanishvili – £4.5bn –former Georgian PM

544. Donald Trump – $3.5bn – US President

745. Sebastian Pinera – $2.7bn –former Chilean president

The global population of billionaires, now put at a record 2,043, marks the biggest annual increase in the 31 years since the magazine began compiling the list.

The number of US billionaires on the list was 565, which Forbes attributed to the recent stock market surge since Mr Trump's November 2016 election.

China was second with 319 billionaires, and Germany was third with 114.

Forbes' top ten:

  1. Bill Gates (Microsoft co-founder): $86bn
  2. Warren Buffett (US investor): $75.6bn
  3. Jeff Bezos (Amazon founder): $72.8bn
  4. Amancio Ortega (Inditex founder): $71.3bn
  5. Mark Zuckerberg (Facebook founder): $56bn
  6. Carlos Slim (Mexican magnate): $54.5bn
  7. Larry Ellison (Oracle co-founder): $52.2bn
  8. Charles Koch (US businessman): $48.3bn
  9. David Koch (US businessman): $48.3bn
  10. Michael Bloomberg (Bloomberg founder): $47.5bn