- 1963 to 196411,727
- 1965 to 196611,364
- 1967 to 196912,363
- 1970 to 19717,856
- 1972 to 19747,780
- 1975 to 19766,802
- 1977 to 19798,488
- 1980 to 19813,585
- 1982 to 19844,555
- 1985 to 19865,130
- 1987 to 19894,710
- 19901,301
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