user: Question: What year was Tim Holden first elected?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Results', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Pennsylvania 1', 'Bob Brady', 'Democratic', 1998.0, 'Re-elected', 'Bob Brady (D) unopposed']
SQL:

assistant: SELECT "First elected" FROM "Table" WHERE "Incumbent" = 'Tim Holden';