- 1970 to 1971 7,348
- 1972 to 1973 6,538
- 1974 to 1975 6,254
- 1976 to 1977 6,256
- 1978 to 1979 7,298
- 1980 to 1981 3,266
- 1982 to 1983 3,156
- 1984 to 1985 4,359
- 1986 to 1987 4,451
- 1988 to 1989 2,235
- 1990 to 1991 1,666
The preservation of the Duke University Libraries Digital Collections and the Duke Digital Repository programs are supported in part by the Lowell and Eileen Aptman Digital Preservation Fund