| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.8%
|
| -7 | Does not apply | 13 |
3.6%
|
| 0 | No obstacle | 144 |
39.6%
|
| 1 | Minor obstacle | 86 |
23.6%
|
| 2 | Moderate obstacle | 67 |
18.4%
|
| 3 | Major obstacle | 39 |
10.7%
|
| 4 | Very severe obstacle | 12 |
3.3%
|