According to Forbes Magazine, the world's top 20 billionaires have a combined net worth of $899 billion.
Bill Gates comes first with a massive fortune of $79 billion. Even though he stepped down as Microsoft's CEO in 2000, he has topped the rankings for 16 of the last 21 years.
When it comes to the world's top 10 richest individuals, seven are American. The three exceptions are second placed Carlos Slim Helu and his family from Mexico, worth $77 billion, fourth placed Amancio Ortega of Spain who is worth $64.5 billion and tenth placed Liliane Bettencourt of France who has a wealth of $40 billion.
This chart shows the top 10 billionaires worldwide in 2014.
You will find more statistics at Statista