| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
3.9%
|
| -7 | Does not apply | 8 |
7.8%
|
| 0 | No obstacle | 66 |
64.1%
|
| 1 | Minor obstacle | 10 |
9.7%
|
| 2 | Moderate obstacle | 7 |
6.8%
|
| 3 | Major obstacle | 3 |
2.9%
|
| 4 | Very severe obstacle | 5 |
4.9%
|