| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 218 |
42%
|
| 1 | Minor obstacle | 94 |
18.1%
|
| 2 | Moderate obstacle | 204 |
39.3%
|
| 3 | Major obstacle | 3 |
0.6%
|
| 4 | Very severe obstacle | 0 |
0%
|