Source: The data come from this table: http://www.econ.berkeley.edu/~saez/TabFig2008.xls

on Emmanuel Saez’s website at University of California, Berkeley. Methodology

Calculations: All incomes are in 2008 dollars. Between any two years, the share of growth in average incomes accounted for by the richest 10% is 10% of the growth in the average income of the top 10% divided by the growth in the overall average income; the share of growth in average incomes accounted for by the bottom 90% is 90% of the growth in the average income of the bottom 90% divided by the growth in the overall average income. These shares are represented in the pie chart. In periods where one or more categories saw negative income growth and one or more categories saw positive income growth, the pie chart simply represents the group that saw growth, and the text provides details. In periods where every category saw income losses, the pie chart shows shares of losses, and the text provides details.