| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.8%
|
| -7 | Does not apply | 4 |
1.1%
|
| 0 | No obstacle | 103 |
28.6%
|
| 1 | Minor obstacle | 36 |
10%
|
| 2 | Moderate obstacle | 76 |
21.1%
|
| 3 | Major obstacle | 84 |
23.3%
|
| 4 | Very severe obstacle | 54 |
15%
|