Nigeria is home to a growing number of millionaires thanks to the country’s rising gross domestic product, local real estate and equity markets, according to a report in IndependentOnline.

The number of people in Africa’s top oil-producing country with investable assets of at least $1 million increased by 44 percent in the last six years to 15,700, Johannesburg-based New World Wealth wrote in a report published today. By 2017, that number is expected to jump to 23,000, the report said.

The oil and gas industry is the source of 24 percent of this wealth, IndependentOnline reports.

Nigeria has the third-highest number of millionaires on the continent after South Africa and Egypt, according to the report. Per-capita income in Africa’s most populous country increased more than fivefold to $1,725 in the last six years.

Lagos, Nigeria’s commercial capital, has 9,500 millionaires, or 61 percent of Nigeria’s
millionaire total. Next is Port Harcourt, an oil industry hub, with 1,300 millionaires. The capital, Abuja, has 600 millionaires, according to New World Wealth.

About 26 percent of their $82 billion was held in offshore accounts in 2013, the report said. The bulk of private-banking funds were deposited in the U.K., Switzerland and the Channel Islands.

“Growth in the wealth of high-net-worth individuals is linked to a number of factors
including the country’s GDP, the local real estate market and the local equity market,”
Andrew Amoils, senior analyst at New World Wealth, said in the report.

Nigeria has five billionaires, according to the report, including Africa’s richest man,
Aliko Dangote, who does business in cement and sugar. Dangote’s net worth is $25.2 billion. The Bloomberg Billionaires Index ranks him as No. 24.

Nigeria’s Ventures Magazine in 2013 reported that Nigeria has 20 billionaires and Africa has 55, according to BBCNews. Of the 55, nine are South African and eight are Egyptian.

Ventures editor-in-chief Uzo Iweala told BBC that counting the super-rich is a problematic endeavor.

“There is this culture of you don’t necessarily want to show your wealth, considering the gap between rich and poor,” Iweala said. “If you have a lot of money, there are a lot of people that you have to support so we think people may be a little reluctant to be all splashy about what they have and what their assets are.”

Nigeria’s economy grew an average of 8.2 percent each year since 1999, according to IndependentOnline.