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

### Instruction:
How many yards per attempt have net yards greater than 631?

### Inputs:
table_name: table, columns: ['Player', 'Attempts', 'Net yards', 'Yards per attempt', 'Touchdowns']

### Response:
SELECT SUM Yards per attempt FROM table WHERE Net yards > 631