Table:
text: United States House of Representatives elections, 1974
Illinois
Illinois
District Incumbent Party First_elected Result_ Candidates
Illinois 3 Robert P. Hanrahan Republican 1972 Lost re-election Democratic gain Marty Russo (D) 52.6% Robert P. Hanrahan (R) 47.4%
Illinois 4 Ed Derwinski Republican 1958 Re-elected Ed Derwinski (R) 59.2% Ronald A. Rodger (D) 40.8%
Illinois 6 Harold R. Collier Republican 1956 Retired Republican hold Henry Hyde (R) 53.4% Edward V. Hanrahan (D) 46.6%
Illinois 9 Sidney R. Yates Democratic 1964 Re-elected Sidney R. Yates (D) Unopposed
Illinois 10 Samuel H. Young Republican 1972 Lost re-election Democratic gain Abner J. Mikva (D) 50.9% Samuel H. Young (R) 49.1%

Question: In what year was the first elected incumbent in the United States House of Representatives election from Illinois, 1974, Sidney R. Yates?