Following decades of relative stability, income inequality has risen sharply in the United States since the 1970s. Data from the Congressional Budget Office indicate that between 1979 and 2002, the share of pretax income accruing to households in the top quintile increased by almost 15 percent, from 45.5 percent to 51.5 percent. The increase was greatest for those with very high incomes: The top 1 percent earned 9.3 percent of pretax income in 1979, and 13.4 percent in 2002 - a 44 percent increase. Pretax income shares declined for each of the bottom four quintiles, with the decline sharpest among those making the least: The lowest quintile saw their pretax income share decrease from 5.8 percent to 4.2 percent, a reduction of more than 27 percent.