Services data has gone through many changes over the years. What is now the Service Annual Survey was three separate surveys, namely the Transportation Annual Survey, Annual Survey of Communication Services, and Service Annual Survey. These three surveys were collected under the U.S. Standard Industrial Classification (SIC) until 1998.
Since the 1999 survey year, data has been published using the North American Industry Classification System (NAICS). The 1998 survey year was the final year the U.S. Census Bureau published data for its annual service surveys using the Standard Industrial Classification (SIC) System.
Detailed information about NAICS and provides a comparison of the SIC and NAICS systems: