| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 9 |
2.5%
|
| -7 | Does not apply is a floor in a building (spontaneous) | 29 |
8%
|
| 0 | 314 |
87%
|
|
| 1 | 1 |
0.3%
|
|
| 100 | 8 |
2.2%
|