The ranks of billionaires dwindled over the past year, with their total worth dropping by $400 billion, says the latest list of the world's richest people from Forbes magazine.

There are 2,668 billionaires around the globe, according to Forbes' annual World's Billionaires list, down 87 from the previous year. These billionaires are worth a combined $12.7 trillion.

Forbes cites the Russia-Ukraine war, the COVID pandemic and weaker markets for the dip in the number of billionaires.

The U.S. still tops all countries with the most billionaires at 735, followed by China's 607.

Elon Musk, the Tesla and SpaceX founder topped Forbes' list for the first time ever with a net worth of $219 billion. More than half of the top 10 billionaires earned their fortunes in the technology sector.

Who are the top 10 richest people in the world?

1. Elon Musk ($219 billion). Musk recently joined Twitter's board after claiming a 9% stake in the company.

2. Jeff Bezos ($171 billion). He founded a little company called Amazon. He also has his own aerospace company, Blue Origin.

3. Bernard Arnault and family ($158 billion). Arnault runs LVMH, the company behind brands including Louis Vuitton, Marc Jacobs, and Christian Dior.

4. Bill Gates ($129 billion). Gates co-founded software giant Microsoft.

5. Warren Buffett ($118 billion). The "Oracle of Omaha" is CEO of Berkshire Hathaway, and made his billions through investing.

6. Larry Page ($111 billion). Next time you Google anything, remember Page, who is one of its co-founders.

7. Sergey Brin ($107 billion). Brin co-founded Google with Page.

8. Larry Ellison ($106 billion). Ellison runs software giant Oracle.

9. Steve Ballmer ($91.4 billion). Ballmer once served as CEO of Microsoft. Today, he's owner of the Los Angeles Clippers.

10. Mukesh Ambani $(90.7 billion). Ambani is the chairman and managing director of Reliance Industries, which is involved in multiple industries including petrochemicals and textile