The Statistical Data Archive contains tables with data presented by the North American Industry Classification System (NAICS) and the Standard Industrial Classification (SIC) classification systems. These tables have overlapping years for comparison. These tables were necessary because the federal government in 1997 replaced the SIC system with the NAICS. NAICS made substantial structural improvements in the industrial classification system from the SIC and identified over 350 new industries. At the same time, it caused breaks in time series far more profound than any prior revision of the SIC system. Since 1997 for a few years, the federal government collected data under both classification systems. Many federal government agencies published data using both NAICS and SIC for overlapping years. However, in general, 2002 was the last year data were available classified by the SIC. In the future, Archive tables containing only SIC classified data will not be updated.Older data will be retained for historical purposes.