- 1945 to 19465,434
- 1947 to 19498,307
- 1950 to 19517,516
- 1952 to 19547,661
- 1955 to 19565,933
- 1957 to 19596,967
- 1960 to 19619,072
- 1962 to 196412,770
- 1965 to 196611,352
- 1967 to 196912,353
- 19707,089
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