- 1945 to 19465,252
- 1947 to 19498,136
- 1950 to 19517,331
- 1952 to 19547,475
- 1955 to 19565,763
- 1957 to 19596,786
- 1960 to 19618,898
- 1962 to 196412,587
- 1965 to 196611,160
- 1967 to 196912,143
- 19707,044
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