| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 |
3.9%
|
| -7 | Does not apply | 17 |
11.2%
|
| 0 | No obstacle | 70 |
46.1%
|
| 1 | Minor obstacle | 11 |
7.2%
|
| 2 | Moderate obstacle | 26 |
17.1%
|
| 3 | Major obstacle | 12 |
7.9%
|
| 4 | Very severe obstacle | 10 |
6.6%
|