| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.8%
|
| -7 | Does not apply | 36 |
10%
|
| 0 | No obstacle | 199 |
55.4%
|
| 1 | Minor obstacle | 57 |
15.9%
|
| 2 | Moderate obstacle | 38 |
10.6%
|
| 3 | Major obstacle | 16 |
4.5%
|
| 4 | Very severe obstacle | 10 |
2.8%
|