The economic census has been taken as an integrated program at 5-year intervals since 1967 and before that for 1954, 1958, and 1963. Prior to that time, individual components of the economic census were taken separately at varying intervals. The range of industries covered in the economic censuses expanded substantially between 1967 and 1992. In 2002, census coverage added landscape architecture, landscaping services, veterinary services, and pet care, industries previously classified as agricultural services.
With these additions, the economic census and the separate census of governments collectively cover roughly 96 percent of all economic activity. Because of the change from SIC to NAICS in 1997, Comparative Statistics (classified by SIC) is the only 1997 Economic Census report completely compatible with prior census data. CD-ROMs issued from the 1987 and 1992 Economic Censuses contain databases for nearly all data published from those two censuses, plus a few additional files covering selected sectors for 1982 and 1977.