Source: US. Bureau of Labor Statistics
Industry based on 2002 North American Industry Classification System (NAICS). Please consult the U.S. Census Bureau (http://www.census.gov/cgi-bin/sssd/naics/naicsrch?chart=2002) for additional information about NAICS.
US. Bureau of Labor Statistics, All Employees: Construction in Illinois [ILCONS], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/ILCONS, December 11, 2016.