| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 11 |
0.8%
|
| -7 | Does not apply | 44 |
3.3%
|
| 0 | No obstacle | 499 |
37.3%
|
| 1 | Minor obstacle | 242 |
18.1%
|
| 2 | Moderate obstacle | 174 |
13%
|
| 3 | Major obstacle | 232 |
17.4%
|
| 4 | Very severe obstacle | 135 |
10.1%
|