| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 17 |
2.2%
|
| -7 | Does not apply is a floor in a building (spontaneous) | 197 |
25.9%
|
| 0 | 366 |
48.2%
|
|
| 10 | 4 |
0.5%
|
|
| 20 | 6 |
0.8%
|
|
| 30 | 10 |
1.3%
|
|
| 40 | 5 |
0.7%
|
|
| 50 | 15 |
2%
|
|
| 100 | 140 |
18.4%
|