- 1908 to 19092,506
- 1910 to 19112,588
- 1912 to 19143,051
- 1915 to 19162,667
- 1917 to 19196,825
- 1920 to 19213,367
- 1922 to 19245,127
- 1925 to 19263,534
- 1927 to 19293,779
- 1930 to 19312,616
- 1932 to 19331,950
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