AUGUSTA, Maine — Updated U.S. Census figures released today show that Maine is the whitest and oldest state in the nation, two trends that could have significant policy implications.

Maine and Vermont have consistently traded the distinction of the nation’s least racially diverse state, and the most recent U.S. Census Bureau data show no change in that respect.

The bureau estimates that 95.3 percent of Maine’s population is white, compared to 95.2 percent in Vermont. Nationally, about 66 percent of the population identifies itself as white.

Additionally, the median age in Maine — already the nation’s oldest state — is growing as the number of Mainers who are 45 or older swells and the number of residents under age 18 declines.

Maine and Vermont also share the distinction of having the smallest percentage of the population under age 5. That’s not surprising to education officials, who have watched enrollment shrink from nearly 240,000 statewide in 1978 to about 194,200 in 2007.

“We have been seeing decreases of 3,000 to 4,000 children per year, and we expect that to continue,” said David Connerty-Marin, spokesman for the Maine Department of Education.

The problem is most severe in rural Maine, where some towns are struggling to justify the costs of keeping schools open for a dwindling number of students. Connerty-Marin said the Census data underscore the reasons for the department’s controversial mandate that school districts consider reorganizing and potentially consoli-dating.

“It’s a difficult balance,” he said. “In some areas, you can’t close the smallest schools because there are no other schools nearby.”

The number of births in Maine rose slightly between 2000 and 2006, according to Donald Lemieux with the Maine Center for Disease Control and Prevention’s Office of Data Research and Vital Statistics. But the 14,150-plus births in Maine in 2006 is still well below the more than 17,000 recorded in 1989, he said.

The Census Bureau is gearing up to perform the next decennial census in 2010, which is based on extensive surveying. The data released today are Census 2000 figures that have been updated by bureau staff primarily using birth and death data, in-migration and out-migration information from Internal Revenue Service forms and international migration from the American Community Survey.

“These are not projections,” said Robert Bernstein, a bureau spokesman. “They are based on administrative records. But they are not from a survey.”

Nationwide, the median age is 36.8 compared to 42 in Maine.

Maine’s median age has increased by more than three years since 2000. At that time, Maine was the fourth-oldest state, with a median age of 38.6, according to the census.

The youngest state in the nation, by comparison, is Utah with a median age of 28.7 — more than 13 years younger than Maine’s. Utah also has the largest proportion of children under age 5 at 10 percent, roughly double the percentage in Maine.

The state with the highest proportion of residents age 65 or older is Florida at 17 percent. Roughly 15 percent of Maine’s population is 65 or older.

On the issue of racial diversity, four states have populations where the majority of people identify themselves as either Hispanic or nonwhite: These so-called “majority-minority” states were Hawaii, New Mexico, California and Texas along with Washington, D.C.

The Census Bureau also reported that:

Washington, D.C., has the highest proportion of women at 52.7 percent while Alaska had the highest proportion of men at 52.1 percent.

California had the largest combined “American Indian and Alaska Native” population with roughly 739,000 residents.

The top 10 counties where Hispanic residents are the majority of the population are all located in Texas.