| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.6%
|
| -7 | Does not apply is a floor in a building (spontaneous) | 30 |
8.3%
|
| 0 | 324 |
90%
|
|
| 10 | 1 |
0.3%
|
|
| 20 | 1 |
0.3%
|
|
| 100 | 2 |
0.6%
|