| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
2.1%
|
| -7 | Does not apply | 20 |
8.3%
|
| 0 | No obstacle | 71 |
29.6%
|
| 1 | Minor obstacle | 30 |
12.5%
|
| 2 | Moderate obstacle | 50 |
20.8%
|
| 3 | Major obstacle | 38 |
15.8%
|
| 4 | Very severe obstacle | 26 |
10.8%
|