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

### Instruction:
What Year has a Result smaller than 20.31, and a World Rank of 5th?

### Inputs:
table_name: table, columns: ['Year', 'Result', 'World Rank', 'Location', 'Date']

### Response:
SELECT AVG Year FROM table WHERE Result < 20.31 AND World Rank = 5th