| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 9 |
2.5%
|
| -7 | Does not apply | 14 |
3.9%
|
| 0 | No obstacle | 124 |
34.6%
|
| 1 | Minor obstacle | 94 |
26.3%
|
| 2 | Moderate obstacle | 94 |
26.3%
|
| 3 | Major obstacle | 22 |
6.1%
|
| 4 | Very severe obstacle | 1 |
0.3%
|