In general, circulation figures are usually available for U.S. and Canadian publications in the sources listed below.
Ulrich's Periodicals Directory - Hodges Stacks PN4699.U47 1943,1947,1951,1953,1956,1959,
Ayer Directory of Publications (Title varies) - Hodges Stacks PN4699.A94 1881, 1920s & 1930s (lacks some years), 1970-1986
Full text 1880 through 1922 are online from the Library of Congress:http://lcweb2.loc.gov/diglib/vols/loc.gdc.sr.sn91012091/default.html
Gale Directory of Publications and Broadcast Media - Hodges Stacks PN4699 .A94 1987-2009; latest year in Reference
Standard Periodical Directory - Storage PN4699.S83 1965-1999
Serials Directory - Hodges Stacks PN4699 .S47 1988/89-1992