- 1950 to 19517,525
- 1952 to 19536,702
- 1954 to 19556,093
- 1956 to 19576,094
- 1958 to 19596,078
- 1960 to 19619,082
- 1962 to 196310,195
- 1964 to 196512,145
- 1966 to 196710,769
- 19688,495
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