WASHINGTON (CNN) - The number of Americans living in poverty jumped to 35.9 million last year, up by 1.3 million, while the number of those without health care insurance rose to 45 million from 43.6 million in 2002, the U.S. government said in a report Thursday.

The percentage of the U.S. population living in poverty rose to 12.5 percent from 12.1 percent -- as the poverty rate among children jumped to its highest level in 10 years, the Census Bureau said in an annual report. The rate for adults 18-to-64 and 65-and-older remained steady.

The bureau also said the share of aggregate income for the lowest 20 percent of Americans fell to 3.4 percent from 3.5 percent.

Democratic politicians were quick to seize on the new data, and none was quicker than their presidential nominee, Sen. John Kerry, D-Mass. He said the statistics "underscore the fundamental choice at stake in this election."

"Four more years of an administration that puts the narrow interests of the few ahead of the interests of most Americans, or new leadership that will serve as a champion for the middle-class and those struggling to join it," he said in a written statement.

Sen. Judd Gregg, R-N.H., released a statement noting that the Census data covered the year 2003 and "does not include the full effect of the president's tax relief."

Gregg, chairman of the Senate Health, Education, Labor and Pensions Committee, took aim at Kerry, accusing the Massachusetts senator of planning to raise taxes and increase government spending and regulation.

But analysts have said the poverty rate typically tracks the broad economy, rising during a recession and falling in boom times. America has struggled to recover from the 2001 slump, and job creation has lagged behind overall growth.

Children and most racial minorities again fared worse than the overall population in 2003, according to the Census report. The rate of child poverty rose to 17.6 percent from 16.7 percent in 2002 -- boosting the number of poor children to 12.9 million.

The poverty rate of of African Americans remained nearly twice the national rate, with 24.4 percent of blacks living below the poverty line in 2003, slightly higher from 24.1 percent a year earlier. Hispanic incomes decline

While the real median income for the entire country remained steady, households with Hispanic householders, who can be of any race, reported a decline in median income of 2.6 percent.

Non-Hispanic white household median income remained about $48,000, black households held at $30,000, while Asian households were steady at $55,500.

The West, at $46,820, Northeast, at $46,742, and Midwest, at $44,732, saw no change in median household income, but the South fell 1.5 percent to $39,823.

Women saw a decline in their earnings for the first time since 1995, falling 0.6 percent to $30,724, putting the female-to-male earnings ratio -- for full-time, year-round workers -- at 76 cents on the dollar, a penny lower than 2002.

The number of Americans living without insurance jumped 1.4 million last year, the government said in a report on Thursday. (For more on the report, click here).

Medicaid, the federal health insurance program for the poor, saw an increase in people covered to 35.6 million from 33.2 million while those covered by Medicare, the federal health program for the elderly, rose to 39.5 million from 38.4 million people.

The Office of Management and Budget at the Census Bureau defined the poverty threshold in 2003 as $18,810 for a family of four; $14,680 for a family of three; $12,015 for a family of two; and $9,393 for an individua

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