What makes a billionaire? A recent report from Fortune magazine found that the world’s most elite — and most wealthy — are on the rise, and it could be due, in part, to a college degree.

The Fortune report detailed that 52 living billionaires hold a degree from Harvard University, while nearly 28 hold degrees from the University of Pennsylvania. At Cambridge University, 11 recent grads are worth more than $1 billion. An Ivy League degree, however, isn’t the only thing that a makes a billionaire a billionaire. Although 68 percent of billionaires hold a four-year degree, one-in-three never went to college – or dropped out before they finished.

US leads the billionaire pack with 515 citizens pulling in a net worth that surpasses $2 billion; New York is home to 96 billionaires, San Francisco has 20 billionaires and Houston has 14. Outside of the US, Hong Kong has 75 billionaires to its name, Moscow, 74, London, 67 and Mumbai, 30. Twenty billionaires reside in Tokyo. China – the US’ closest competitor – has 157 billionaires, claiming more than 89 percent are “self-made.”

Since 2014, the billionaire population has grown by 7 percent, reaching an all-time high of 2,325. Despite the unforgiving global climate, they haven’t stopped earning.