- 1868 to 1869 1,690
- 1870 to 1874 1,904
- 1875 to 1879 1,748
- 1880 to 1884 1,756
- 1885 to 1889 2,429
- 1890 to 1894 3,186
- 1895 to 1899 2,798
- 1900 to 1904 3,133
- 1905 to 1909 3,000
- 1910 to 1914 3,570
- 1915 to 1919 7,478
- 1920 to 1923 4,828
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