- 1963 to 196411,464
- 1965 to 196611,090
- 1967 to 196912,073
- 1970 to 19717,723
- 1972 to 19747,555
- 1975 to 19766,660
- 1977 to 19798,339
- 1980 to 19813,545
- 1982 to 19844,514
- 1985 to 19865,097
- 1987 to 19894,654
- 19901,270
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