user: Question: How many were in attendance when the result was L 20-17?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 6, 1981', 'at Atlanta Falcons', 'L 27-0', 57406.0]
SQL:

assistant: SELECT "Attendance" FROM "Table" WHERE "Result" = 'L 20-17';