OLYMPIA, Wash. - State officials say Washington's population is growing, but at a slower rate than just a few years ago.

The state's official population estimate for 2009 is 6,668,200.

Chief demographer Theresa Lowe says the population grew by about 1.2 percent from last year. The most recent yearly peak was in 2006, at 1.9 percent. Lowe says the economic downturn is one of the factors crimping migration to the state.

Most of the population growth since the 2000 census has been concentrated in Western Washington. King, Pierce, Snohomish and Clark counties have posted the biggest gains in those nine years.

The fastest-growing counties on a percentage basis since 2000 are Franklin, Clark, Thurston and Kittitas.