| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | 
                                    
                                    0%
                                 | 
| 1 | Cubic meters | 19 | 
                                    
                                    13%
                                 | 
| 2 | Gallons | 2 | 
                                    
                                    1.4%
                                 | 
| 3 | Cubic feet | 2 | 
                                    
                                    1.4%
                                 | 
| 4 | Other | 66 | 
                                    
                                    45.2%
                                 | 
| 5 | Liters | 57 | 
                                    
                                    39%
                                 | 
| Sysmiss | 4 |