By Beth Pinsker NEW YORK (Reuters) – 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 percent 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. (See the full list at https://forbes. …