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

### Instruction:
What chng has a rank greater than 6, with 12 as a prev?

### Inputs:
table_name: table, columns: ['Rank', 'Prev', 'Player', 'Rating', 'Chng']

### Response:
SELECT Chng FROM table WHERE Rank > 6 AND Prev = 12