- 1905 to 19093,004
- 1910 to 19143,576
- 1915 to 19197,482
- 1920 to 19246,656
- 1925 to 19295,070
- 1930 to 19344,082
- 1935 to 19395,817
- 19402,660
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