user: Question: What was the number of rounds on the Hidden Valley Raceway?
Columns: ['Rd.', 'Race Title', 'Circuit', 'City / State', 'Date', 'Winner', 'Team', 'Report']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Clipsal 500', 'Adelaide Street Circuit', 'Adelaide , South Australia', '21–24 February', 'Jamie Whincup', 'Triple Eight Race Engineering', 'report']
SQL:

assistant: SELECT "Rd." FROM "Table" WHERE "Circuit" = 'Hidden Valley Raceway';