- 1930 to 19313,249
- 1932 to 19332,594
- 1934 to 19353,211
- 1936 to 19374,452
- 1938 to 19394,263
- 1940 to 19414,578
- 1942 to 19433,785
- 1944 to 19454,561
- 1946 to 19476,023
- 1948 to 19496,296
- 19506,383
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