- 19272,633
- 1928 to 19291,952
- 1930 to 19312,630
- 1932 to 19331,965
- 1934 to 19352,544
- 1936 to 19373,689
- 1938 to 19393,359
- 1940 to 19413,546
- 1942 to 19432,847
- 19442,354
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