The World Billonaires Mid Year List.

The ranks of the world’s billionaires continue to scale new heights–and stretch to new corners of the world. Our global wealth team found a record 1,645 billionaires with an aggregate net worth of $6.4 trillion, also a record, up from $5.4 trillion a year ago. We unearthed 268 new ten-figure fortunes, including 42 new women billionaires, both also records. In total, there are 172 women on the list, more than ever before and up from 138 last year.

Bill Gates is back on top after a four-year hiatus, reclaiming the title of world’s richest person from telecom mogul Carlos Slim Helu of Mexico, who ranked No. 1 for the past four years. Gates, whose fortune rose by $9 billion in the past year, has held the top spot for 15 of the past 20 years. Spanish clothing retailer Amancio Ortega (best known for the Zara fashion chain) retains the No. 3 spot for the second year in a row, extending his lead over Warren Buffett, who is again No. 4. American gambling tycoon Sheldon Adelson, who added $11.5 billion to his pile, makes it back into the top ten for the first time since 2007. Another first: A record net worth of $31 billion was needed to make the top 20, up from $23 billion last