user: Question: How many rounds did Shirley van der Lof go?
Columns: ['Team', 'Driver', 'Class', 'Chassis', 'Engine', 'Rounds']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['van Amersfoort Racing', 'Rahel Frey', 'C', 'Dallara F307', 'Volkswagen', '1–8']
SQL:

assistant: SELECT "Rounds" FROM "Table" WHERE "Driver" = 'Shirley van der Lof';