- 1980 to 1981 14
- 1982 to 1983 5
- 1984 to 1985 37
- 1986 to 1987 24
- 1988 to 1989 0
- 1990 to 1991 3
- 1992 to 1993 1
- 1994 to 1995 9
- 1996 to 1997 4
- 1998 to 1998 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