| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 |
5.8%
|
| -7 | Does not apply | 15 |
14.6%
|
| 0 | No obstacle | 59 |
57.3%
|
| 1 | Minor obstacle | 10 |
9.7%
|
| 2 | Moderate obstacle | 7 |
6.8%
|
| 3 | Major obstacle | 5 |
4.9%
|
| 4 | Very severe obstacle | 1 |
1%
|