| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| 1 | Cubic meters | 211 |
51.8%
|
| 2 | Gallons | 70 |
17.2%
|
| 3 | Cubic feet | 1 |
0.2%
|
| 4 | Other | 125 |
30.7%
|
| Sysmiss | 193 |