Illinois statistical areas  The statistical areas of the United States of America comprise the metropolitan statistical areas (MSAs), the micropolitan statistical areas (μSAs), and the combined statistical areas (CSAs) currently defined by the United States Office of Management and Budget (OMB). Most recently on March 6, 2020, the Office of Management and Budget defined 1114 statistical areas for the United States, including 11 combined statistical areas, 13 metropolitan statistical areas, and 19 micropolitan statistical areas in the State of Illinois. The table below shows the recent population of these statistical areas and the 102 counties of Illinois. The table below describes the 43 United States statistical areas and 102 counties of the State of Illinois with the following information: