| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.4%
|
| -7 | Does not apply | 10 |
2%
|
| 0 | No obstacle | 123 |
24.1%
|
| 1 | Minor obstacle | 173 |
33.9%
|
| 2 | Moderate obstacle | 110 |
21.5%
|
| 3 | Major obstacle | 84 |
16.4%
|
| 4 | Very severe obstacle | 9 |
1.8%
|