user: Question: What is the total outcome for the Clay surface on April 21, 1996?
Columns: ['Outcome', 'Date', 'Tournament', 'Surface', 'Opponent in the final', 'Score in the final']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Winner', 'October 30, 1988', 'Baden , Switzerland ITF $10,000', 'Clay', 'Katarzyna Nowak', '6–1, 6–1']
SQL:

assistant: SELECT COUNT("Outcome") FROM "Table" WHERE "Surface" = 'Clay' AND "Date" = 'April 21, 1996';