- 1946 to 1949 41
- 1950 to 1954 2
- 1955 to 1959 40
- 1960 to 1964 96
- 1965 to 1969 155
- 1970 to 1974 190
- 1975 to 1979 212
- 1980 to 1984 194
- 1985 to 1989 127
- 1990 to 1994 132
- 1995 to 1999 132
- 2000 to 2002 20
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