These statistics are sent by Illinois to the Federal Bureau of Investigation who publishes a document called Crime in the United States the current document is listed above and provides stats for 2013.
Index Part I Crimes
These documents are counts of arrests and offenses for the Uniform Crime Reports (UCR) Index Part I crimes:
Index Part II Crimes
The UCR County-level Arrest files also report arrests for additional Index Part II crimes such as
Drug possession or sale
The data was originally collected by the Federal Bureau of Investigation (FBI) from reports submitted by agencies and states participating in the UCR Program. Each agency or jurisdiction is uniquely identified in the collection by the UCR Originating Agency Identifier (ORI).
In describing this data collection, the agency, jurisdiction, and ORI are used synonymously. Detailed discussions of reporting procedures are found in the Uniform Crime Reporting Handbook (Washington, DC: U.S. Government Printing Office, 1980) and in the codebooks for the ICPSR's Agency-level UCR data collections (see ICPSR 9028).