| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 18 |
2.4%
|
| -7 | Does not apply is a floor in a building (spontaneous) | 196 |
25.8%
|
| 0 | 539 |
70.9%
|
|
| 20 | 1 |
0.1%
|
|
| 50 | 1 |
0.1%
|
|
| 100 | 5 |
0.7%
|