Although the global economy has been mired in sluggishness for years amid stagnant wages in many developed countries, the world's wealthiest have never been richer or greater in number, according to a billionaire census published this week by research and analysis outfit Wealth-X.

All told, the world held a record 2,473 billionaires in 2015 – up 6.4 percent over the year. This group of individuals held a collective net worth of roughly $7.7 trillion, also a record. Putting that sum in perspective, if the world's billionaires joined together to form an ultra-elite nation of their own, their combined wealth would eclipse the gross domestic products of every country in the world except those of the U.S. and China.

"Although the overall size of the billionaire population is small, the impact of billionaires on the global economy is significant," the report says, noting that there is "only one billionaire for every 2.95 million people on the planet."

Europe again stood as the premier destination for billionaires, as more than 800 ultrawealthy individuals staked claims within the continent's borders. Another 645 billionaires were tied to Asia, while 628 called North America home. It's worth noting, though, that the combined wealth of North America's billionaires – a whopping $2.56 trillion – still eclipsed the billionaire wealth total from every other geographic region.

That said, the report indicates that the Asia-Pacific region is "poised to eventually take over the Americas," as it managed to produce "four times more billionaires than the Americas during 2015 and thus leads all regional groups in terms of growth rate of billionaire population and wealth."

Region Number of Billionaires Billionaire Growth (Year Over Year) Total Wealth ($Billions) Wealth Growth (Year Over Year) Europe 806 4% $2,330 -1.9% Middle East 166 7.8% $413 9% Africa 41 2.5% $114 -14% North America 628 3.1% $2,371 8% Latin America & the Caribbean 154 0.7% $511 -4.5% Asia 645 15.2% $1,410 19.6% Pacific 33 -2.9% $97 -27.8%

A potentially more concerning trend highlighted by the report is that billionaires in 2015 continued their flight to liquid assets. The world's richest held more than 22 percent of their wealth in cash or easily convertible assets like stocks or bonds last year, marking the highest liquidity level on record. The report indicates that between 2014 and 2015, there was a "considerable ramp-up in liquidity events."

This trend suggests the world's wealthiest are trying to shield themselves from international economic volatility, shying away from risky ventures and protecting their nest eggs from economic downturns. Theoretically, these are the folks with the strongest connections to the business world, and those who are likely employing financial advisors and portfolio managers with proven track records.

If the ultrarich are starting to head for the bunker, it's probably not a good sign for everyone else.

"Billionaires are taking money off the table where available," the report says, citing "uncertainties in the economy" as a complicating factor.

But who are these wildly wealthy individuals? The report indicates the average billionaire is in his or her early 60s, holds a bachelor's degree and earned much of his or her wealth through ventures and not inheritance. About 56 percent of the world's billionaires are self-made, while 13 percent inherited their wealth and another 31 percent inherited some of their assets but invested in their own interests to grow their cache.

"The common denominator of the world's billionaires is their entrepreneurialism," the report says. "In most instances, achieving billionaire status requires more than just inheritance; 87 percent of billionaires, up from 81 percent in 2014, made the majority of their fortunes themselves."

The other common denominator among the lion's share of the world's billionaires is a Y chromosome. The world holds only 294 female billionaires, accounting for less than 12 percent of the group's population. This demographic's net worth accounts for only 11.4 percent of total billionaire wealth.

Encouragingly, more than 56 percent of the world's billionaires cite "philanthropy" as an interest or hobby in which they're involved. Another 31 percent are passionate about traveling, and nearly 15 percent said boating was a hobby of theirs.

"The Bill and Melinda Gates Foundation and the Giving Pledge have instilled a sense of humanitarian responsibility in billionaires to use their vast wealth to make a difference in the world," the report says.

Charitable donations and philanthropic ventures often come with tax incentives, but billionaires' proclivity to give is undoubtedly a positive in the U.S. and beyond amid growing concern about income inequality.