The primary sources for this report are computerized data files on military personnel maintained by the Defense Manpower Data Center (DMDC). In addition, the Bureau of Labor Statistics (BLS) provides the bulk of the comparison data on the national population. Though the data sources have remained constant, refinements have been made over the years, most of them in regard to the civilian comparisons. Starting with the report for FY 1994, Census data were adjusted to provide a more accurate comparison for military applicants and accessions (yearly average rather than last month of the fiscal year). Age comparisons for prior-service enlisted accessions to the Selected Reserve were also adjusted, from the 18- to 44-year-old civilian labor force to the 20- to 39-year-old civilian labor force. Comparisons for Selected Reserve enlisted members were changed from 18- to 44-year-old civilians to 18- to 49-year-olds. Starting with data for FY 1995, a further age refinement was introduced for comparisons with the officer corps. Previously the comparison group for Active Component officers comprised civilian workforce college graduates who were 21 and older. This was adjusted by establishing an upper bound at age 49, making the more precise comparison, college graduates aged 21 to 49 who are in the workforce. In addition, beginning with the FY 1995 Population Representation report, DMDC provided edited, rather than raw, data on applicants for enlistment. In FY 1997, prior service accession data for the Active Component were added. U.S. Coast Guard representation statistics were included for the first time in FY 1998. A refinement to the age range of the civilian comparison group for Active Component prior service enlisted accessions—recently added—was made in FY 1999. The age range was extended from 18-24 year-olds to 17-35 year-olds, to better reflect the older composition of recruits with previous military experience. A brief description of the data sources for FY 1999 follows: