New York (CNN Business) Mark Zuckerberg had a rough 2018. Facebook was plagued by scandal and data breaches, and Zuckerberg's wealth shrank along with his company's fortunes.

The Facebook CEO's net worth fell by $9 billion. He slipped three places on the Forbes 2018 global billionaires list , which the publication released Tuesday. The magazine now estimates Zuckerberg's net worth to be $62.3 billion — down from $71 billion last year.

had a brutal 2018 : The company was battered with data breaches and multiple government investigations into its practices. Its stock lost more than a fifth of its value.

Zuckerberg's wealth is tied to Facebook's performance because he owns nearly 17% of the stock, according to Forbes.

Other notable billionaires

The top three people on the list were unchanged compared to last year.

Amazon AMZN founder Jeff Bezos, whose wealth rose $19 billion from 2018 to $131 billion to this year, is in first place.

Microsoft MSFT co-founder Bill Gates landed in second place, with his net worth rising to $96.5 billion this year from $90 billion last year. In third place is billionaire investor Warren Buffett. His net worth slipped $1.5 billion to $82.5 billion.

Walmart WMT Only two people in the top 20 of the list are women. The granddaughter of LOreal's founder, Francoise Bettencourt-Meyers, is in 15th place with $49.3 billion. Alice Walton of thefamily in 17th place with $44.4 billion.

Forbes said that the number of billionaires shrank for only the second time in a decade, citing last year's tumultuous stock market and slowing global economy.

The total combined net worth for its billionaires shrank $400 billion to just $8.7 trillion. Nearly 250 people dropped out of the list, which was the most since 2009 at the height of the Great Recession.

Kylie Jenner

The publication said reality TV star and entrepreneur Kylie Jenner became the youngest-ever self-made billionaire last year. It estimates her company, Kylie Cosmetics is worth $900 million.

It reached that calculation by using a "conservative" revenue multiple compared to other makeup industry peers. Forbes said Kyle Cosmetics brought in about $360 million in sales last year — and Jenner owns 100% of the company.

So where did the other $100 million come from? Forbes said she has that money in cash.