| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 35 |
8.1%
|
| 1 | Minor obstacle | 46 |
10.7%
|
| 2 | Moderate obstacle | 107 |
24.9%
|
| 3 | Major obstacle | 163 |
37.9%
|
| 4 | Very severe obstacle | 79 |
18.4%
|