Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What is the average year that has a car that won 0 stages with a position of DNF?

### Inputs:
table_name: table, columns: ['Year', 'Class', 'Vehicle', 'Position', 'Stages won']

### Response:
SELECT AVG Year FROM table WHERE Class = car AND Stages won = 0 AND Position = dnf