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

### Instruction:
What is Tries Against, when Try Diff is +15?

### Inputs:
table_name: table, columns: ['Team', 'Tries for', 'Tries against', 'Try diff', 'Points for', 'Points against', 'Points diff']

### Response:
SELECT Tries against FROM table WHERE Try diff = +15