user: Question: What rounds did Phoenix International Raceway host?
Columns: ['Rnd', 'Date', 'Length', 'Race Name', 'Track', 'Location', 'Pole Position', 'Winning Driver']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'March 18', 'Jimmy Bryan 150', 'mi (km)', 'Phoenix International Raceway', 'Avondale , Arizona', 'Bobby Unser', 'Bobby Unser']
SQL:

assistant: SELECT "Rnd" FROM "Table" WHERE "Track" = 'Phoenix International Raceway';