| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 20 |
1.2%
|
| -7 | Does not apply is a floor in a building (spontaneous) | 408 |
24.5%
|
| 0 | 806 |
48.5%
|
|
| 15 | 2 |
0.1%
|
|
| 20 | 12 |
0.7%
|
|
| 25 | 2 |
0.1%
|
|
| 30 | 11 |
0.7%
|
|
| 40 | 9 |
0.5%
|
|
| 50 | 35 |
2.1%
|
|
| 60 | 1 |
0.1%
|
|
| 70 | 3 |
0.2%
|
|
| 80 | 1 |
0.1%
|
|
| 90 | 1 |
0.1%
|
|
| 100 | 352 |
21.2%
|