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

### Instruction:
What's the average destroyed with a 1990 over 12, more than 1 damaged, 6 survivors, and a to Iran less than 4?

### Inputs:
table_name: table, columns: ['Aircraft', '1990', 'destroyed', 'damaged', 'to Iran', 'survived']

### Response:
SELECT AVG destroyed FROM table WHERE 1990 > 12 AND damaged > 1 AND to Iran < 4 AND survived = 6