user: Question: What was the total opponents points for the game were the Oilers scored 21?
Columns: ['Game', 'Date', 'Opponent', 'Result', 'Oilers points', 'Opponents', 'Oilers first downs', 'Record', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'real', 'real', 'real', 'text', 'real']
Sample row: [1.0, 'Sept. 7', 'at Pittsburgh Steelers', 'Loss', 17.0, 31.0, 16.0, '0–1', 54386.0]
SQL:

assistant: SELECT SUM("Opponents") FROM "Table" WHERE "Oilers points" = 21.0;