user: Question: what is the circuit when the date is 16 April?
Columns: ['Race Title', 'Circuit', 'City / State', 'Date', 'Winner', 'Team']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Amaroo', 'Amaroo Park', 'Sydney , New South Wales', '5 March', 'John Bowe', 'Dick Johnson Racing']
SQL:

assistant: SELECT "Circuit" FROM "Table" WHERE "Date" = '16 April';