On Wednesday, Forbes magazine unveiled its 25th annual ranking of the richest men on the planet based on the reporting of 50 journalists across 13 countries.

These reporters not just meet with these candidates and those associated with them, but also minutely track their moves such as the deals they negotiate, their real estate transactions, their luxury purchases and the causes they give to.

The final net worth of these billionaires are based on a valuation of the individuals' assets, including stakes in public and private companies, real estate, yachts, art and cash-and also account for debt.

The 2011 ranking reinforces the observed shifts in global economic power with a steep increase in the number of billionaires from the emerging BRIC economies: the number of billionaires from China almost doubled to 115, while with 101 and 30 representations respectively, Russia and Brazil saw a two-thirds jump. India had 55, which is six more than last year's representation.

However, the top ten list, though it has has not changed much in composition from last year has seen some significant repositioning within; the only newcomer, however, is Christy Walton (and family) of Walmart-fame who moved up two slots from #12 to replace Karl Albrecht.

Start slideshow to view a gallery of the 10 richest billionaires in the world today in order of rank:

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