user: Question: Name the first downs for points against being 0
Columns: ['Week', 'Date', 'Result', 'Record', 'Opponent', 'Points For', 'Points Against', 'First Downs', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'text', 'real', 'real', 'real', 'real']
Sample row: [1.0, 'September 19', 'Win', '1–0', 'at Buffalo Bills', 49.0, 37.0, 19.0, 46206.0]
SQL:

assistant: SELECT "First Downs" FROM "Table" WHERE "Points Against" = 0.0;