Union membership in Hawaii declined by 12,000 last year to 123,000, according to the U.S. Bureau of Labor Statistics.

Hawaii also dropped from being the state with the second-highest percentage of union members in the country to third. In 2010 about 21.8 percent of workers were union members in Hawaii, down from 23.5 in 2009.

The number of workers in unions declined sharply last year across the country, with the national percentage slipping to 11.9 percent, the lowest rate in more than 70 years.

According to the bureau, New York had the highest unionization rate of any state, at 24.2 percent, followed by Alaska at 22.9 percent and Hawaii at 21.8 percent. Hawaii led Alaska in 2009 with 23.5 percent versus 22.3 percent. North Carolina had the lowest rate last year, at 3.2 percent, with Arkansas and Georgia tied for second lowest at 4 percent.

The report found that the number of workers in unions fell by 612,000 last year to 14.7 million, an even larger decrease than the overall 417,000 decline in the total number of Americans working.

"It was a very tough year for unionized workers," said John Schmitt, a senior economist with the Center for Economic and Policy Research in Washington. "We’re seeing declines in the private sector, and we’re seeing declines in the public sector."

The number of private-sector workers in unions fell by 339,000 to 7.1 million, while the number of public-sector union members fell by 273,000 to 7.6 million.

The percentage of private-sector workers in unions fell to 6.9 percent, down from 7.2 percent, the lowest rate for private-sector workers in more than a century, labor historians said.

In 2009, for the first time in U.S. history, government employees accounted for more than half the nation’s union membership, but the percentage of government workers in unions fell to 36.2 percent last year, down from 37.4 percent the previous year.

The Bureau of Labor Statistics said the overall unionization rate last year was down from 12.3 percent in 2009 and 20.1 percent in 1983, when there were 17.7 million union members. The peak unionization rate was 35 percent during the mid-1950s, after a surge in unionization during the Great Depression and after World War II.

Last year’s drop in union membership stemmed partly from large-scale layoffs in several sectors with many union members, most notably construction, manufacturing, teaching and local government.

In one piece of good news for unions, the bureau said that median weekly earnings for union members — $917 — remained higher than the $717 in earnings for workers not in unions.

Barry Hirsch, a labor economist at Georgia State University, sees many reasons for the decline in unionization over the past few decades.

"Unionized companies obviously raise wages and benefits for their workers, and while they often raise productivity, typically they’re at a cost disadvantage and unionized companies haven’t fared as well," he said.

Another factor that has pushed down unionization, he said, is that companies have grown more ideologically opposed to unions and more aggressive about resisting organizing drives.