| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 135 |
54%
|
| 1 | Minor obstacle | 76 |
30.4%
|
| 2 | Moderate obstacle | 34 |
13.6%
|
| 3 | Major obstacle | 5 |
2%
|
| 4 | Very severe obstacle | 0 |
0%
|