- 1942 to 19443,811
- 1945 to 19464,456
- 1947 to 19497,391
- 1950 to 19516,692
- 1952 to 19546,840
- 1955 to 19565,115
- 1957 to 19596,126
- 1960 to 19618,377
- 1962 to 196412,058
- 1965 to 196610,692
- 1967 to 196911,697
- 19706,653
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