Despite plunging oil prices and fluctuating currencies, the world’s richest people have defied global economic turmoil and grown their wealth yet again. Bill Gates occupies the top spot once more with a total net worth of $79.2 billion. The American business magnate and philanthropist is followed by Mexican telecom tycoon, Carlos Slim Helu, with $77.1 billion. Meanwhile, Walmart’s Christy Walton ranks as the richest woman and eighth overall on this year’s list with a net worth of $41.7 billion.