The Middle East's billionaires – with a combined net worth of US$354 billion – hold a higher percentage of total wealth than in any other region in the world, findings from the Wealth-X and UBS Billionaire Census 2013 show. Forty percent of the Middle East's ultra high net worth (UHNW) wealth is being held by the region's 157 billionaires, compared to 28 percent in Europe, 22 percent in North America and 18 percent in Asia. Saudi Arabia leads the region with the most billionaires (64). Middle East is the region with the fourth most billionaires – after Europe (766), North America (552) and Asia. Middle Eastern billionaires increased their wealth in the last year by US$39 billion (12.4 percent) with five additional billionaires (3.3 percent).