For the first time in nearly a decade, more residents left Hawai'i than moved here, according to newly released 2009 population estimates from the U.S. Census Bureau.

A poor economy and rising unemployment are likely the reasons, said research and statistics officer Eugene Tian of the state Department of Business, Economic Development and Tourism.

"When our economy is good, more people move to Hawai'i," he said.

The Census data show that from July 1, 2008, to July 1, 2009, an estimated 5,298 more people moved to the Mainland from Hawai'i than migrated here. During that same period, 4,033 more people from foreign countries came to live in the state than moved away.

That left a net migration loss of 1,265 people.

Normally the influx of outsiders to Hawai'i offsets any decline from folks moving to the Mainland, but that did not happen this time, Tian said.

He said two factors influence domestic migration between Hawai'i and the Mainland: military movement and the economy. The last net migration loss occurred in 2001, except for a net loss in 2007 attributed to a major military deployment to the Mainland, according to Tian.

Even though the state experienced a net loss of residents, the total population increased slightly from July 1, 2008, to July 1, 2009, thanks to "natural" growth from 19,093 births, minus 9,792 deaths.

The Census Bureau estimated the state's population at 1,295,178, up 0.6 percent — or 7,697 people — from 2008.

Tian said the average annual population growth rate between 2000 and 2009 was 0.7 percent, or an average of 9,046 new residents per year.

Hawai'i ranked 42nd in the nation in terms of 2009 resident population, accounting for only 0.42 percent of the U.S. population of 307 million, the bureau said.

California remained the most populous state, with an estimated 37 million people, or 12 percent of the nation's total. Rounding out the top five states were Texas (24.8 million), New York (19.5 million), Florida (18.5 million) and Illinois (12.9 million).

Texas gained more people than any other state between July 1, 2008, and July 1, 2009, with 478,000 new residents, followed by California (381,000), North Carolina (134,000), Georgia (131,000) and Florida (114,000), according to Census Bureau estimates.

Wyoming showed the largest percentage growth (2.12 percent), followed by Utah (2.10 percent), Texas (1.97 percent) and Colorado (1.81 percent).

The only three states to lose population over the period were Michigan (-0.33 percent), Maine (-0.11 percent) and Rhode Island (-0.03 percent).

This the final set of Census Bureau state population estimates to be published before the official 2010 Census population counts are released next December, said Census Bureau Director Robert Groves in a news release.

"We are focused now on ensuring we get a complete and accurate count in 2010. The census counts will not only determine how many U.S. House seats each state will have but will also be used as the benchmark for future population estimates," he said.

When calculating total population growth using natural and migration estimates, the math doesn't always add up because the Census Bureau includes a "residual" number to represent the change in population that cannot be attributed to any specific demographic component.