WASHINGTON — The top 400 taxpayers in the United States paid an average tax rate of 18 percent in 2010, the lowest since 2007, according to Internal Revenue Service data released Friday.

The wealthiest taxpayers earn most of their money from capital gains, which are taxed at preferential rates, letting them pay effective rates far below the 35 percent marginal income tax rate that year.

People who earn all of their income from wages often pay a higher tax rate than the very wealthiest Americans, said Leonard Burman, director of the Tax Policy Center in Washington.

The comparable rate for all taxpayers in 2010 was 11.8 percent, and that includes more than 40 percent of households that paid no income taxes that year.

The data show the highest-income U.S. households rebounding from the recession in 2009. The minimum adjusted gross income needed for the exclusive list rose 28 percent, to $99.1 million, and the average income of those on the list reached $265 million.

The IRS data offer a glimpse into the finances of the wealthiest U.S. households, who now receive more than twice the share of national income than they did in 1995.

These taxpayers had 1.31 percent of all adjusted gross income in the U.S. in 2010 and paid 2.01 percent of the income taxes, though they make up less than 0.001 percent of the population, according to the IRS.

They received 16 percent of all capital gains and 5 percent of all taxable interest. They also made 4.3 percent of all charitable contributions. “Capital gains are hugely skewed,” Burman said.

As Congress lowered capital gains rates starting in 1997, the top taxpayers responded by earning more of their income as gains and less in salary. In 2010, the top 400 taxpayers made 6.4 percent of their income in salaries and wages, down from 16.7 percent in 2000.

The IRS didn’t identify any of the individuals, and the composition of the list changes from year to year.

Under tax laws in effect in 2010, the top rate for long- term capital gains and dividends was 15 percent and the top rate on wage income was 35 percent.

Since then, rates for top taxpayers have increased. Starting in 2013, the top capital gains rate rose to 20 percent and the top rate on ordinary income increased to 39.6 percent.

On top of that, to help fund the 2010 health-care law, Congress imposed a 3.8 percent tax on unearned income, including capital gains and dividends.

President Obama wants to raise the wealthiest Americans’ taxes even more by imposing limits on their deductions and taxing the carried interest of private-equity managers as ordinary income instead of capital gains.

The data were posted on the IRS website Friday and first reported by Al Jazeera.