| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 3 |
0.8%
|
| 0 | No obstacle | 66 |
17.4%
|
| 1 | Minor obstacle | 95 |
25%
|
| 2 | Moderate obstacle | 78 |
20.5%
|
| 3 | Major obstacle | 96 |
25.3%
|
| 4 | Very severe obstacle | 42 |
11.1%
|