| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 22 |
1.7%
|
| -7 | Does not apply | 51 |
3.9%
|
| 0 | No obstacle | 714 |
54%
|
| 1 | Minor obstacle | 267 |
20.2%
|
| 2 | Moderate obstacle | 150 |
11.3%
|
| 3 | Major obstacle | 65 |
4.9%
|
| 4 | Very severe obstacle | 54 |
4.1%
|