- 1944135
- 1945 to 19492,180
- 1950 to 19542,389
- 1955 to 19591,784
- 1960 to 19642,092
- 1965 to 19693,227
- 1970 to 1974791
- 1975 to 1979473
- 1980 to 1984540
- 1985 to 1989493
- 1990 to 1994871
- 1995 to 1999624
- 2000 to 200484
- 2005 to 20071
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