user: Question: What was the earliest year that the result 21-17?
Columns: ['Year', 'Date', 'Winner', 'Result', 'Loser', 'Location']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1933.0, 'October 15', 'New York Giants', '56-0', 'Philadelphia Eagles', 'Polo Grounds']
SQL:

assistant: SELECT MIN("Year") FROM "Table" WHERE "Result" = '21-17';