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

### Instruction:
What is the average win as a percentage of German racer Rudi Altig, who has ridden in over 79 races?

### Inputs:
table_name: table, columns: ['Name', 'Nationality', 'Races won', 'Races ridden', 'Win average']

### Response:
SELECT AVG Win average FROM table WHERE Nationality = german AND Name = rudi altig AND Races ridden > 79