user: Question: How many rounds were run at calder park?
Columns: ['Round', 'Circuit', 'State', 'Date', 'Winning driver']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Sandown', 'Victoria', '13 April', 'John Smith']
SQL:

assistant: SELECT COUNT("Round") FROM "Table" WHERE "Circuit" = 'calder park';