In the world's biggest economy, one in eight Americans and almost one in four blacks lived in poverty last year, the U.S. Census Bureau said on Tuesday, both ratios virtually unchanged from 2004.

The survey also showed 15.9 percent of the population, or 46.6 million, had no health insurance, up from 15.6 percent in 2004 and an increase for a fifth consecutive year, even as the economy grew at a 3.2 percent clip.

It was the first year since President George W. Bush took office in 2001 that the poverty rate did not increase. As in past years, the figures showed poverty especially concentrated among blacks and Hispanics.

In all, some 37 million Americans, or 12.6 percent, lived below the poverty line, defined as having an annual income around $10,000 for an individual or $20,000 for a family of four. The total showed a decrease of 90,000 from the 2004 figure, which Census Bureau officials said was "statistically insignificant."

The last time poverty declined was in 2000, the final year of Bill Clinton's presidency, when it fell to 11.3 percent.

The stagnant poverty picture drew attention from Democrats and others who said not enough is being done to help the nation's poor.

"Far too many American families who work hard and play by the rules still wind up living in poverty," said Rep. George Miller (news, bio, voting record) of California, the top Democrat on the House Education and Workforce Committee.

Around a quarter of blacks and 21.8 percent of Hispanics were living in poverty. Among whites, the rate edged down to 8.3 percent from 8.7 percent in 2004.

"Among African Americans the problem correlates primarily to the inner-city and single mothers," said Michael Tanner of CATO Institute, a free-market think tank in Washington. He noted that blacks also suffer disproportionately from poor education and lower quality jobs.

Black median income, at $30,858, was only 61 percent of the median for whites.

Some 17.6 percent of children under 18 and one in five of those under 6 were in poverty, higher than for any other age group.

Still, real median household income rose by 1.1 percent to $46,326 from $45,817 -- its first increase since 1999. This was taken as a positive move by Republicans and administration officials.

"While we still have challenges ahead, our ability to bounce back is a testament to the strong work ethic of the American people, the resiliency of our economy, and pro-growth economic policies, including tax relief," said Office of Management and Budget Director Rob Portman.

The figures contained wide regional variations, ranging from a median household income of $61,672 in New Jersey to $32,938 for Mississippi.

Major cities with the highest proportions of poor people included Cleveland with 32.4 percent and Detroit with 31.4 percent under the poverty line.