| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 8 |
7.2%
|
| -7 | Does not apply | 11 |
9.9%
|
| 0 | No obstacle | 52 |
46.8%
|
| 1 | Minor obstacle | 29 |
26.1%
|
| 2 | Moderate obstacle | 5 |
4.5%
|
| 3 | Major obstacle | 5 |
4.5%
|
| 4 | Very severe obstacle | 1 |
0.9%
|