user: Question: Visitor of Minnesota has what average attendance?
Columns: ['Date', 'Visitor', 'Score', 'Home', 'Decision', 'Attendance', 'Record']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['December 1', 'Calgary', '2 – 4', 'Detroit', 'Joseph', 20066.0, '13–7–3–1']
SQL:

assistant: SELECT AVG("Attendance") FROM "Table" WHERE "Visitor" = 'Minnesota';