| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 70 |
40.5%
|
| 1 | Minor obstacle | 18 |
10.4%
|
| 2 | Moderate obstacle | 29 |
16.8%
|
| 3 | Major obstacle | 13 |
7.5%
|
| 4 | Very severe obstacle | 43 |
24.9%
|