| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 39 |
2.9%
|
| -7 | Does not apply is a floor in a building (spontaneous) | 308 |
23.3%
|
| 0 | 507 |
38.3%
|
|
| 10 | 5 |
0.4%
|
|
| 20 | 4 |
0.3%
|
|
| 30 | 9 |
0.7%
|
|
| 35 | 1 |
0.1%
|
|
| 40 | 6 |
0.5%
|
|
| 50 | 23 |
1.7%
|
|
| 52 | 1 |
0.1%
|
|
| 60 | 3 |
0.2%
|
|
| 70 | 9 |
0.7%
|
|
| 80 | 11 |
0.8%
|
|
| 85 | 1 |
0.1%
|
|
| 90 | 7 |
0.5%
|
|
| 100 | 389 |
29.4%
|