user: Question: What is the average year that has a Car that won 0 stages with a position of DNF?
Columns: ['Year', 'Class', 'Vehicle', 'Position', 'Stages won']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [2004.0, 'Car', 'Mitsubishi', '10', '0']
SQL:

assistant: SELECT AVG("Year") FROM "Table" WHERE "Class" = 'Car' AND "Stages won" = '0' AND "Position" = 'DNF';