- 1945 to 19465,249
- 1947 to 19498,132
- 1950 to 19517,328
- 1952 to 19547,472
- 1955 to 19565,760
- 1957 to 19596,783
- 1960 to 19618,822
- 1962 to 196412,510
- 1965 to 196611,085
- 1967 to 196912,067
- 19706,968
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