| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 19 |
1.4%
|
| -7 | Does not apply is a floor in a building (spontaneous) | 43 |
3.2%
|
| 0 | 1229 |
91.9%
|
|
| 8 | 1 |
0.1%
|
|
| 10 | 2 |
0.1%
|
|
| 20 | 3 |
0.2%
|
|
| 40 | 1 |
0.1%
|
|
| 60 | 1 |
0.1%
|
|
| 100 | 38 |
2.8%
|