Hawaii's population is becoming older and more Caucasian, according to new U.S. Census Bureau estimates released today.

But the state remains one of the most racially diverse in the nation with the highest percentage population of Asians and native Hawaiians and Pacific Islanders.

The census estimates, however, show a continued decline in both groups.

Asians, alone or in combination, made up 54 percent of the state's population, down from 58.2 percent in 2000; native Hawaiians and Pacific Islanders accounted for 21.8 percent of the population, also a decrease from 23.4 percent in 2000.

Caucasians, alone or in combination, comprised 43 percent of Hawaii's population on July 1, 2008, an increase from 40.3 percent in 2000.

State officials question if the Census Bureau numbers are accurate.

“;We have concerns,”; said Eugene Tian, the statistics officer for the state Department of Business, Economic Development and Tourism.

Tian suspects there could be a problem with how the Census Bureau estimates the race of people born in Hawaii.

He said the ethnic categories for births do not match the census categories, and that the census is not calculating race correctly.

However, he said there is no way of knowing if the numbers are correct until next year's census, when everyone is counted.

“;We know that births (of Asians, native Hawaiians and Pacific Islanders) have not decreased,”; Tian said.

If the census numbers are correct, he said, then it means more Caucasians are moving here and more Asians and Pacific Islanders are moving away.

Tiva Aga, a former member of the Census Advisory Committee for Native Hawaiians and Pacific Islanders, said she believes Pacific Islanders are being undercounted because of language barriers and a mistrust by some of answering census questions.

Aga, who works as an adviser to the Census Bureau, said an accurate count is needed to make sure Hawaii gets its fair share of federal dollars.

“;We're working hard to get the word out,”; she said. “;There are many that we have to find where they are located around the islands.”;

The census numbers also show Hawaii's population is getting older, with the median age rising from 37.8 in 2007 to 38 last year.

The number of school-age children decreased by an average of 2,309 per year between 2000 and 2008.