Forbes 400 Totals
In 2011, the combined wealth of the Forbes 400 was $1.53 trillion. The World's Billionaires list from Forbes in 2011 included 1210 people (minimum worth to make the list is $1b), and totaled $4.5 trillion.
Link: (http://www.forbes.com/sites/luisakroll/2011/09/21/inside-the-list-facts-...)