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

### Instruction:
Which year did the school with the mascot of the Vikings join?

### Inputs:
table_name: table, columns: ['School', 'Location', 'Mascot', 'County', 'Year Joined', 'Year Left']

### Response:
SELECT Year Joined FROM table WHERE Mascot = vikings