The data are based on the Census of Government Employment for 1997, 2002, and 2007. These data, derived from public records, contain no confidential information. Because the data come from a census of all state and local governmental units, they are not subject to sampling error, but they do contain nonsampling error. Data users who generate their own estimates using data from these tables must cite the Census Bureau as the source of the original data only. Users will find additional information on the survey methodology at the hyperlinks below. See the classification manual for survey content definitions.