Among occupational groups, education, training, and library occupations and protective service workers had the highest unionization rates in 2004 at 37.6 and 37.3 percent, respectively.
Construction and extraction occupations; installation, maintenance, and repair occupations; transportation and material moving occupations; community and social services occupations; and production occupations also had higher-than-average rates. In 2004 the average union membership rate for all occupations was 12.5 percent.
Sales and related occupations and farming, fishing, and forestry occupations had the lowest unionization rates at 3.6 and 3.1 percent, respectively.
These 2004 data on union membership are from the Current Population Survey. Unionization data are for wage and salary workers. Find out more in "Union Members in 2004" (PDF) (TXT), news release USDL 05-112.
Bureau of Labor Statistics, U.S. Department of Labor, The Economics Daily, Unionization rates by occupation, 2004 at https://www.bls.gov/opub/ted/2005/feb/wk1/art03.htm (visited November 29, 2022).