- 1945 to 19465,270
- 1947 to 19498,158
- 1950 to 19517,343
- 1952 to 19547,487
- 1955 to 19565,777
- 1957 to 19596,808
- 1960 to 19618,915
- 1962 to 196412,611
- 1965 to 196611,194
- 1967 to 196912,192
- 19707,075
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