All Employees: Professional and Business Services: Professional, Scientific, and Technical Services in Illinois was 440.20000 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, All Employees: Professional and Business Services: Professional, Scientific, and Technical Services in Illinois reached a record high of 455.00000 in May of 2023 and a record low of 255.30000 in October of 1991. Trading Economics provides the current actual value, an historical data chart and related indicators for All Employees: Professional and Business Services: Professional, Scientific, and Technical Services in Illinois - last updated from the United States Federal Reserve on April of 2024.