user: Question: What is the pa listed when the ends won is 21?
Columns: ['Skip (Club)', 'W', 'L', 'PF', 'PA', 'Ends Won', 'Ends Lost', 'Blank Ends', 'Stolen Ends']
Types: ['text', 'real', 'real', 'real', 'real', 'real', 'real', 'real', 'real']
Sample row: ['Cindy Ricci (Lampman)', 4.0, 1.0, 32.0, 33.0, 20.0, 16.0, 10.0, 7.0]
SQL:

assistant: SELECT "PA" FROM "Table" WHERE "Ends Won" = 21.0;