A record 357 new billionaires were minted last year as the already very wealthy saw their combined fortunes soar to an all-time high of $9.2tn (£6.8tn) - more than three times the UK’s gross domestic product.

The number of billionaires worldwide increased by 14.9% to 2,754 in 2017 as the wealthy benefited from the “remarkable performances in equity markets and global economy”, according to a report by ultra-rich research firm Wealth-X.

The Wealth-X billionaire census 2018, published on Tuesday, found a “dramatic improvement” in billionaires’ assets, with their combined wealth increasing by $1.8bn – or 24% – to $9.2tn, as the very rich streak further away from the general population.

“Although the year 2017 had its fair share of political upheaval, the remarkable performances in equity markets and the global economy supported robust wealth gains across the financial, commodity, technology and industrial sector,” Winston Chesterfield, a director of Wealth-X, said. “In a rapidly shifting geopolitical environment, the influence on the world economy of this most exclusive group of individuals is continuing to rise.”

The 10 richest billionaires collectively hold assets worth more than $660bn.

Jeff Bezos, the founder of Amazon, is the world’s richest person. His fortune has increased by $34.2bn in the past year to take his net worth to $133bn. In just one day last month, Bezos’s fortune increased by $12bn, after Amazon reported much higher than expected profits.

Bezos, 54, who founded Amazon in his Seattle garage in 1994, owns 16% of the retailer. He also owns all of space exploration company Blue Origin and the Washington Post newspaper, which he bought for $250m in 2013.

The US is home to by far the largest population of billionaires, with 680, a 10% increase on 2016. However, the number of super-wealthy in China are increasing quickly, with a 36% increase to 338 billionaires. Germany, India, Switzerland, Russia and Hong Kong all have more billionaires than the UK, which lost four billionaires last year to reduce the total to 90.

“The UK was the only country in the top 10 to record both a decline in billionaire numbers and combined net worth, largely owing to Brexit-related effects that contributed to the weaker development of economic growth, equities, real estate assets and the currency compared with most of its peers,” the report said.

The UK’s richest person is petrochemicals industrialist Jim Ratcliffe, who this week told the Sunday Times Rich List that it had been underestimating his wealth. The newspaper bumped Ratcliffe, 65, from 18th to first place in its rich list, with a £21bn fortune.

The number of female billionaires increased at a faster rate than males for the first time in the Wealth-X annual census. The female billionaire population increased by 18% to 321, compared with a 14% increase in the number of males. However, women only make up 11.7% of the total.