- 19092,159
- 1910 to 19199,000
- 1920 to 19299,622
- 1930 to 19398,819
- 1940 to 194914,195
- 1950 to 195914,177
- 1960 to 196921,973
- 1970 to 197913,732
- 1980 to 198914,005
- 1990 to 19976,605
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