| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.9%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 76 |
34.7%
|
| 1 | Minor obstacle | 51 |
23.3%
|
| 2 | Moderate obstacle | 42 |
19.2%
|
| 3 | Major obstacle | 31 |
14.2%
|
| 4 | Very severe obstacle | 17 |
7.8%
|