Sonoma County's experience as a fast-growth area faded further into history on Thursday as the latest population figures showed a 0.51 percent increase in the past year, continuing an 11-year trend.

The last time the county grew by as much as 1 percent was 2001, and growth in the past 10 years (2003-12) totals 4.5 percent.

Those figures are a dramatic shift from the postwar boom period, when the county grew by 43 percent in the 1950s, 39 percent in the &‘60s and 46 percent in the &‘70s.

That era, when the county's business establishment sought to emulate San Jose's suburban sprawl, gave rise to the environmental movement and the advent of restrictive zoning and urban growth boundaries in Sonoma County.

The State Department of Finance's latest population report, released Thursday, pegged the county's population at 489,283 on July 1, with a one-year gain of just 2,505 people.

The county had 5,179 births and 4,036 deaths in the past year, for a natural increase of 1,143, the report said.

Net migration — counting moves to and from other counties, states and countries — added another 1,362 residents.

In 2011, Sonoma County posted a 0.56 percent growth rate, gaining 2,694 people over the year.

The county's minimal expansion in 2012 mirrored California, which grew to 37.8 million people on July 1, up 0.68 percent over the year.

Ben Stone, executive director of the Sonoma County Economic Development Board, said the county's sustained period of growing at about a half percent a year represents a "happy medium" between the breakneck pace of the boom era and the current economic reality.

Some nearby counties have less growth, he said, and the state report pegged Marin County at 0.21 percent growth in 2012, Solano at 0.38 percent and Lake at a population loss of 0.04 percent.

Mendocino was about the same as Sonoma with 0.56 percent growth, while Napa posted a 0.69 percent gain.

A report prepared for the Economic Development Board last year by Moody's Analytics predicted that the county would grow by 1.2 percent to 1.3 percent a year for the next three years (2013-15). That would be a significant changed from the current pattern.

The growth outlook "could be worse," Stone said, adding his anecdotal impression that many newcomers to the county are young couples who find Sonoma more affordable than Marin or San Francisco.

But the county's slow population growth, combined with an aging population, is creating a "talent shortage" for businesses, said Cynthia Murray, president of the North Bay Leadership Council.

"We hear it from company after company that they can't find good people," said Murray, whose group represents 44 businesses with about 25,000 employees in Sonoma, Marin and Napa counties.

As older people move out of the workforce, employers are finding a scarcity of skilled workers, especially those with training or experience in science, technology, engineering and mathematics, she said.

The trend is part of a national phenomenon, Murray said, with more than 3 million jobs unfilled because of a shortage of qualified workers.

You can reach Staff Writer Guy Kovner at 521-5457 or guy.kovner@pressdemocrat.com.