| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 41 |
6.4%
|
| 1 | Minor obstacle | 106 |
16.4%
|
| 2 | Moderate obstacle | 122 |
18.9%
|
| 3 | Major obstacle | 283 |
43.9%
|
| 4 | Very severe obstacle | 93 |
14.4%
|