- 1930 to 1939 204
- 1940 to 1949 173
- 1950 to 1959 2
- 1960 to 1969 0
- 1970 to 1979 0
- 1980 to 1989 0
- 1990 to 1999 0
- 2000 to 2009 0
- 2010 to 2013 2
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