Formal monthly statistical compilations were initiated by W. N. C. Carlton and carried on by George B. Utley. In 1942, Stanley Pargellis merged this separate statistical report with the departmental reports (Record Group 02/20/22). Title varies: Statistical Record of Service Activities and Technical Work of the Library, 1917-1932; Statistics of the Public Service and Technical Division, 1933-1942.

Monthly reports prepared by the Librarian's Office contain statistics on all areas of library activity. Included are figures on readers, collection usage, correspondence, telephone inquiries, reproductions, exhibitions, acquisitions (gift and purchase), cataloguing, binding, and library size. Beginning in June, 1918, figures cumulate for the year.

For statistics for the period following 1942, see Record Group 03/20/21, Departmental Reports, and reports filed in the Conservation, Reader Services, and Technical Services Departments, Record Groups 10-12.