user: Question: what year was the first elected incumbant Sidney R. Yates?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Illinois 3', 'Robert P. Hanrahan', 'Republican', 1972.0, 'Lost re-election Democratic gain', 'Marty Russo (D) 52.6% Robert P. Hanrahan (R) 47.4%']
SQL:

assistant: SELECT "First elected" FROM "Table" WHERE "Incumbent" = 'Sidney R. Yates';