- 19194,448
- 1920 to 19213,646
- 1922 to 19245,403
- 1925 to 19263,839
- 1927 to 19294,071
- 1930 to 19313,033
- 1932 to 19343,330
- 1935 to 19363,694
- 1937 to 19395,018
- 1940 to 19414,260
- 1942 to 19433,547
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