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

### Instruction:
What is the Date that has MARTIN of 7–9% and no Undecided?

### Inputs:
table_name: table, columns: ['Source', 'Date', 'MARTIN', 'GRÜNE', 'Others', 'Undecided']

### Response:
SELECT Date FROM table WHERE Undecided = – AND MARTIN = 7–9%