South Africa is home to six dollar billionaires this year, with retail tycoon Christo Wiese leading the pack after almost tripling his personal wealth this past year. His worth now sits close to R105-billion, or about $7.3-billion at the current exchange rate.South Africa is home to the second-most dollar billionaires in Africa, behind Egypt, which has eight.story_article_left1Nigeria has only five dollar billionaires this year, because most of the country's wealth is tied to the oil price, which has halved.There were a total of 29 dollar billionaires in Africa in 2015, a continent that is largely dependent on its natural resources for the big money.The country with the most dollar billionaires isthe US, with 536, among them Bill Gates, Warren Buffett and Mark Zuckerberg.China has 213 billionaires, and third on the list is Germany, which, despite its comparatively small population, has 103 dollar billionaires.When it comes to population size and economic growth rates, South Africa and South Korea are comparable at the moment, with populations of around 50million and growth rates of around 1%. But South Korea has 30 dollar billionaires.Although South Africa has historically made its money from its mineral wealth, today's dollar billionaires come from a wide range of sectors, which shows how the country has managed to diversify.story_article_right2The six dollar billionaires are Wiese; Glencore mining magnate Ivan Glasenberg; British businessman and property tycoon John Whittaker; pharmaceutical executive Stephen Saad; German-born furniture mogul Bruno Steinhoff and PSG founder Jannie Mouton.Except for Glasenberg and Whittaker, who were only included on the list later, the other four dollar billionaires have been on the Rich List for almost a decade, growing their collective wealth from R7.6-billion in 2006 (about $1.1-billion back then) to R152.7-billion (about $10.6-billion at the current exchange rate).Although South Africa might be home to only a handful of dollar billionaires, the number of dollar millionaires has been growing by 9% since 2007, with black people, Indians and coloureds speeding up this growth.According to the New World Wealth report, South Africa will be home to 55 000 dollar millionaires by 2017.There are about 163 000 dollar millionaires in Africa, 42% of them living in South Africa.prinsloop@sundaytimes.co.za..