The number of Americans without health insurance fell by over 1 million in 2007, to 45.7 million, from 47 million in 2006, the U.S. Census Bureau reports.

It was the first annual decline in the rate in 7 years, the bureau says.

The percentage without health insurance in 2007 was 15.3%, down from 15.8% in 2006.

The drop was largely due to an increase in the number of children getting health insurance through government-funded programs, the Census Bureau says.

The data was collected before the recent economic downturn, some observers pointed out.

The bureau reports 253.4 million had health insurance in 2007, up from 249.8 million the year before. Of those, 202 million held private health insurance, about the same as the year before, while the number of people covered by government health insurance rose to 83 million from 80.3 million.

The number of uninsured children under 18 declined in the period from 8.7 million (11.7% of children) in 2006 to 8.1 million.

The Northeast and the Midwest had lower uninsured rates in 2007 (11.4%) than the West (16.9%) and the South (18.4%).

Texas remained the state with the highest uninsured rate, 24.4%. At 8.3%, Massachusetts and Hawaii had the lowest uninsured rates, followed by Minnesota (8.5%). Wisconsin (8.8%), Iowa (9.4%), and Hawaii and Maine (9.5%).

Commenting on the data, Karen Ignani, president and chief executive of America’s Health Insurance Plans, Washington, said the number of uninsured still represents “a critical social and economic challenge that the nation must address.”

The slight improvement does not lessen the urgency of providing coverage for the uninsured, she added.

“We need coverage for all Americans, coverage they can afford, and coverage they can keep,” she said.