- 1963 to 196411,457
- 1965 to 196611,085
- 1967 to 196912,067
- 1970 to 19717,716
- 1972 to 19747,548
- 1975 to 19766,655
- 1977 to 19798,335
- 1980 to 19813,541
- 1982 to 19844,510
- 1985 to 19865,088
- 1987 to 19894,647
- 19901,268
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