| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 2 |
1%
|
| 0 | No obstacle | 42 |
20.1%
|
| 1 | Minor obstacle | 120 |
57.4%
|
| 2 | Moderate obstacle | 36 |
17.2%
|
| 3 | Major obstacle | 5 |
2.4%
|
| 4 | Very severe obstacle | 4 |
1.9%
|