AP Photo/Nati Harnik Warren Buffett is the second-richest person in the US, according to Forbes, with an estimated net worth of $67 billion.

There are 12 million millionaires in the world, but only 2,325 billionaires.

That's an exclusive club, of which the likes of Warren Buffett, Jack Ma, and Oprah Winfrey are members.

Digging into research firm Wealth-X's new Billionaire Census, we found that billionaires have some commonalities.

Such as:

• If there is an average billionaire, he or she is worth around $3 billion. Or roughly one Snapchat.

• Billionaires have a combined wealth of $7.3 trillion, a 12% increase from last year. That's higher than the market capitalization of all the Dow Jones companies put together. Put another way, if all the world's billionaires decided to join forces and become a country, their combined wealth would be greater than the GDP than Japan.

• The 2,325 billionaires control 4% of the wealth in the world. The more inclusive 1% of the world's population controls 40% of the wealth.

• For every three million people on earth there's a single billionaire. Lonely, right?

• Europe has more billionaires than any other region. The Old World has 775 of them.

• The US has more than any other country. America has 571 billionaires, with 57 newly minted members since last year.

• 60% of billionaires made their wealth themselves, like Jack Ma and Larry Ellison. Meanwhile, 26.9% became billionaires from re-investing inherited wealth, and 13% of them inherited their billionaire status straight out.

• Getting to billionaire status takes a while. Your average billionaire is 63 years old, and 93% of the world's billionaire population is over 45.

• Billionaires invest a lot in real estate, at about $160 million per person. They tend to have four properties — it supports "the billionaire lifestyle," the report says.

• Billionaires tend to have "non-real estate luxury assets." They sound really fun. " For example, one in 30 billionaires owns a sports team or a racehorse," the report says. "Other significant luxury assets include yachts, planes, cars, and art."

• Billionaires are into matrimony. 65% of them are married.

• Billionaires love the Ivy League. While billionaires went to over 700 different universities, the Ivies have the most grads: 25 went to the University of Pennsylvania, 22 went to Harvard, and 20 went to Yale.

• But a surprising number of billionaires don't have a college degree. 35% never finished undergrad.

• Billionaires tend to work in finance. Almost 20% of billionaires made their careers on Wall Street or its equivalents.

And they're most likely living in New York.





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