| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 20 |
2.8%
|
| -7 | Does not apply | 3 |
0.4%
|
| 0 | No obstacle | 221 |
31%
|
| 1 | Minor obstacle | 197 |
27.6%
|
| 2 | Moderate obstacle | 143 |
20.1%
|
| 3 | Major obstacle | 104 |
14.6%
|
| 4 | Very severe obstacle | 25 |
3.5%
|