| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 104 |
29.4%
|
| 1 | Minor obstacle | 56 |
15.8%
|
| 2 | Moderate obstacle | 80 |
22.6%
|
| 3 | Major obstacle | 86 |
24.3%
|
| 4 | Very severe obstacle | 28 |
7.9%
|