Data for the most recent year, including size-of-firm data, are also available in the
latest Covered Employment and Wages publication.
Historical data are available back to 1976, but beginning in 2001 data are reported
using the North American Industry Classification System (NAICS). Prior data are organized
by Standard Industrial Classification (SIC). Because of significant differences between
these methods of industrial classfication, data for 2001 forward are not comparable with prior