The richest 400 Americans are significantly richer in 2013 than they were last year and younger Americans are accumulating wealth at a faster clip than their baby boomer counterparts, according to two reports released Monday. The annual Forbes 400 wealthiest Americans list showed that total wealth climbed 19% in the last year to $2.02 trillion, up from $1.7 trillion, with an average net worth per individual of $5 billion, up from $ 4.2 billion in 2012. It now takes $1.3 billion in assets just to get on the list. Atop the list for another year was Bill Gates, who at 57 has a net ...