| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 6 |
3.8%
|
| 1 | Minor obstacle | 20 |
12.7%
|
| 2 | Moderate obstacle | 58 |
36.9%
|
| 3 | Major obstacle | 49 |
31.2%
|
| 4 | Very severe obstacle | 24 |
15.3%
|