user: Question: What date is the crowd larger than 20000?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Venue', 'Crowd', 'Date']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Melbourne', '13.15 (93)', 'St Kilda', '13.11 (89)', 'MCG', 13000.0, '17 May 1941']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Crowd" > 20000.0;