Each year, Forbes supplies its readers with a ranked guide to the world’s richest people. Since John D. Rockefeller was confirmed as the first billionaire (in U.S. dollars) in 1916, the number of billionaires has crept slowly upward.

To understand more about the upper echelons of the world’s most affluent citizens, Wealth-X conducts an annual Billionaire Census. A widely quoted authority on global wealth, Wealth-X looks beyond the names and personalities to examine assets and lifestyles, including where the wealthiest get their money and where they’re most likely to spend it.

According to the recent study, those with a net worth of US$1 billion or more “form one of the most exclusive clubs in the world; there is only one billionaire for every 2.95 million people on the planet.” The world’s billionaire population is now a record-setting 2,473 with a total wealth of $7.7 trillion.

The number of billionaires may fluctuate with the global economy (there was a sharp drop in their numbers worldwide in 2009) and the number of billionaires among the ultra high net worth (UHNW) population (those with US$30 million and above in net assets) may change as well. In 2015, it was reported that while the increase in the number of billionaires among the UHNW was small (1%), their “wealth accounts for an ever larger share of the world’s UHNW individuals.”

With each census, these are the notable trends. For 2015, the census shows that

Billionaires are holding more liquid assets than in years past.
There continues to be an over-representation of males among billionaires both in numbers (88%) and in total wealth (88.6%).
The wealth of female billionaires is more likely to come from entrepreneurial activity than in past years, when inheritance was their primary source of assets. (This trend holds true among the larger population, with 55% of billionaires self-made and the number with inherited wealth down by 29% since 2014.)
There is an increased diversification of business holdings among billionaires, and a substantial reduction in the number of billionaires coming from the finance, banking and investment industries.
Worldwide wealth is distributed 6% in Europe, 26.1% in Asia, 25.4% in U.S., and the balance divided among the Middle East, Latin America/Caribbean, Africa, and the Pacific. Geographically, the growth in the number and assets of billionaires is most dramatic in Asia.