| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 95 |
25%
|
| 1 | Minor obstacle | 123 |
32.4%
|
| 2 | Moderate obstacle | 84 |
22.1%
|
| 3 | Major obstacle | 75 |
19.7%
|
| 4 | Very severe obstacle | 3 |
0.8%
|