| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 11 |
0.9%
|
| -7 | Does not apply | 29 |
2.4%
|
| 0 | No obstacle | 539 |
44.9%
|
| 1 | Minor obstacle | 172 |
14.3%
|
| 2 | Moderate obstacle | 177 |
14.8%
|
| 3 | Major obstacle | 176 |
14.7%
|
| 4 | Very severe obstacle | 96 |
8%
|