user: Question: In the district called Tennessee 6, how many in total of first elected are there?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Tennessee 1', 'Jimmy Quillen', 'Republican', 1962.0, 'Re-elected', 'Jimmy Quillen (R) 80.2% Sidney S. Smith (D) 19.8%']
SQL:

assistant: SELECT COUNT("First elected") FROM "Table" WHERE "District" = 'Tennessee 6';