| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.8%
|
| -7 | Does not apply | 7 |
1.9%
|
| 0 | No obstacle | 128 |
35.6%
|
| 1 | Minor obstacle | 49 |
13.6%
|
| 2 | Moderate obstacle | 68 |
18.9%
|
| 3 | Major obstacle | 47 |
13.1%
|
| 4 | Very severe obstacle | 58 |
16.1%
|