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

### Instruction:
What ship size had a cargo value of $31,750 in 2006?

### Inputs:
table_name: table, columns: ['Ship size', 'Cargo', '2004', '2005', '2006']

### Response:
SELECT Ship size FROM table WHERE 2006 = $31,750