Statistics are "numerical facts systematically collected" that can be used
1. to support a statement
2. to provide a basis for a theory (or thesis statement)
3. for comparison and contrast
4. to show trends
If the use of statistics is to be valid, you must know what is being measured, how and by whom the material has been gathered, when it was done, and how it can be applied to what you are researching.
Much of the U.S. Government produced statistics are now on the Internet. Consult a Reference Librarian for MORE web site addresses.
Statistics can be found in many places--in periodical articles, in books, in reference books such as encyclopedias and almanacs, and especially in publications of state, federal, and international organizations. As a good starting point in your search for statistics, check the following general publications first.