Richest Are Leaving Even the Rich Far Behind

This is the definition of the concentration of wealth:

Richest Are Leaving Even the Rich Far Behind

From the article:

The share of the nation's income earned by those in this uppermost category has more than doubled since 1980, to 7.4 percent in 2002. The share of income earned by the rest of the top 10 percent rose far less, and the share earned by the bottom 90 percent fell.