| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 17 |
1.3%
|
| -7 | Does not apply | 27 |
2%
|
| 0 | No obstacle | 463 |
34.6%
|
| 1 | Minor obstacle | 272 |
20.3%
|
| 2 | Moderate obstacle | 275 |
20.6%
|
| 3 | Major obstacle | 199 |
14.9%
|
| 4 | Very severe obstacle | 84 |
6.3%
|