user: Question: What is the highest year that a candidate was first elected?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Georgia 2', "Maston E. O'Neal, Jr.", 'Democratic', 1964.0, 'Re-elected', "Maston E. O'Neal, Jr. (D) Unopposed"]
SQL:

assistant: SELECT MAX("First elected") FROM "Table";