The Corporation for National and Community Service reports that 63.4 million Americans volunteered to help their communities in 2009, 1.6 million more than the year before, and the largest single-year spike since 2003. They contributed 8.1 billion hours of service, with an estimated value of nearly $169 billion.

Part-time employees proved the most generous, with a 34 percent volunteer rate, according to the Portland Tribune’s analysis of U.S. Bureau of Labor Statistics. Nearly 29 percent of those with full-time jobs contributed. About 23 percent of unemployed individuals volunteered.

Utah was the top volunteer state, with a rate of more than 44 percent, followed by Iowa, Minnesota, Nebraska and Alaska, all exceeding 37 percent. Large cities were led by Minneapolis-St. Paul; Portland, Oregon; Salt Lake City; Seattle; and Oklahoma City, all with at least a third of their residents taking up a cause.

Mid-size cities, particularly those in the Midwest, have on average higher volunteer rates than large cities, with volunteers also contributing more hours. Mid-size city stars, with a volunteer rate of between 63 and 40 percent include Provo, Utah; Iowa City; Ogden, Utah; Fort Collins, Colorado; and Madison, Wisconsin.