About 61.2 million people volunteered through or for an organization at least once between September 2005 and September 2006, the Bureau of Labor Statistics of the U.S. Department of Labor reported today. The proportion of the population who volunteered was 26.7 percent. This is 2.1 percentage points lower than the volunteer rate in each of the prior 3 years and slightly lower than in 2002, the first year for which comparable data are available. These data on volunteering were collected through a supplement to the September 2006 Current Population Survey (CPS). The supplement was sponsored by the Corporation for National and Community Service. Volunteers are defined as persons who did unpaid work (except for expenses) through or for an organization. The CPS is a monthly survey of about 60,000 households that obtains information on employment and unemployment among the nation's civilian noninstitutional population age 16 and over.