| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
1%
|
| -7 | Does not apply | 5 |
1.3%
|
| 0 | No obstacle | 139 |
35.8%
|
| 1 | Minor obstacle | 212 |
54.6%
|
| 2 | Moderate obstacle | 24 |
6.2%
|
| 3 | Major obstacle | 4 |
1%
|
| 4 | Very severe obstacle | 0 |
0%
|