| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 78 |
50%
|
| 1 | Minor obstacle | 38 |
24.4%
|
| 2 | Moderate obstacle | 22 |
14.1%
|
| 3 | Major obstacle | 15 |
9.6%
|
| 4 | Very severe obstacle | 3 |
1.9%
|