These are places to look if none of the sources listed above had the information you need:
Statistics sources: a subject guide to data on industrial, business, social, educational, financial, and other topics for the United States and internationally. Detroit, Mich.: Gale Research Co., 1962-
Z7551 .S85 [1962-2013 in RECAP; current volume in Stokes (SPIA)]
Indexes statistical publications issued by (1) the U.S. government (American Statistics Index; 2004+ full text); (2) international and intergovernmental sources (Index to International Statistics; 2007+ select full text); and state governments and private sources (Statistical Reference Index). Most sources are available in microfiche.