| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.8%
|
| -7 | Does not apply | 9 |
2.5%
|
| 0 | No obstacle | 196 |
54.4%
|
| 1 | Minor obstacle | 47 |
13.1%
|
| 2 | Moderate obstacle | 47 |
13.1%
|
| 3 | Major obstacle | 34 |
9.4%
|
| 4 | Very severe obstacle | 24 |
6.7%
|