From irs.gov....

When you make money doing other people's tax returns and read information from the IRS, sometimes you encounter facts like these [data is the most recent available]:

Individual income tax returns reporting a tax liability in 2007 faced an average tax rate of 13.8 percent, the same as in 2006. Taxpayers with AGI of at least $410,096, the top 1 percent of taxpayers, accounted for 22.8 percent of AGI in 2007, an increase of 0.8 percentage points. These taxpayers accounted for 40.4 percent of total income tax reported in 2007, an increase from 39.9 percent in the previous year.

Points to note:

1. "reporting a tax liability" means that all those people who did not make enough money to owe the IRS are eliminated from the statistic. In other words, their "taxable income" was zero.

2. Does it bother you that 1% of the taxpayers are paying 40.4% of all the income taxes? On the other end, over 40% of "taxpayers" are paying no income taxes...and in many cases, claiming credits, such as the Earned Income Credit, that provide them with robust refunds anyway.