All Employees: Professional and Business Services: Scientific Research and Development Services in Illinois was 22.30045 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, All Employees: Professional and Business Services: Scientific Research and Development Services in Illinois reached a record high of 44.73648 in January of 2001 and a record low of 18.82136 in June of 2017. Trading Economics provides the current actual value, an historical data chart and related indicators for All Employees: Professional and Business Services: Scientific Research and Development Services in Illinois - last updated from the United States Federal Reserve on March of 2024.