| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 146 |
13.3%
|
| -7 | Does not apply is a floor in a building (spontaneous) | 57 |
5.2%
|
| 0 | 187 |
17.1%
|
|
| 10 | 2 |
0.2%
|
|
| 15 | 1 |
0.1%
|
|
| 20 | 8 |
0.7%
|
|
| 30 | 11 |
1%
|
|
| 33 | 1 |
0.1%
|
|
| 40 | 10 |
0.9%
|
|
| 50 | 44 |
4%
|
|
| 60 | 24 |
2.2%
|
|
| 70 | 17 |
1.6%
|
|
| 77 | 1 |
0.1%
|
|
| 80 | 25 |
2.3%
|
|
| 90 | 4 |
0.4%
|
|
| 99 | 1 |
0.1%
|
|
| 100 | 557 |
50.8%
|