The National Crime Victimization Survey (NCVS), previously the National Crime Survey (NCS), has been collecting data on personal and household victimization through an ongoing survey of a nationally-representative sample of residential addresses since 1973. The survey is administered by the United States Census Bureau (under the United States Department of Commerce) on behalf of the Bureau of Justice Statistics (under the United States Department of Justice). Occasionally there have been extract or supplement files created from the NCVS and NCS data series. This extract contains two data files, a weighted person-based file, and a weighted incident-based file, which contain the "core" counties within the top 40 National Crime Victimization Survey Metropolitan Statistical Areas (MSAs). Core counties within these MSAs are defined as those self-representing primary sampling units that are common to the MSA definitions determined by the Office of Management and Budget for the 1970-based, 1980-based, and 1990-based sample designs. Each MSA is comprised of only the core counties and not all counties within the MSA. The person-based file contains select household and person variables for all people in NCVS-interviewed households in the core counties of the 40 largest MSAs from January 1979 through December 2004. The incident-based file contains select household, person, and incident variables for persons who reported a violent crime within any of the core counties of the 40 largest MSAs from January 1979 through December 2004. Household, person, and incident information for persons reporting non-violent crime are excluded from this file. The 40 largest MSAs were determined based on the number of household interviews in an MSA.