| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 41 |
3.1%
|
| -7 | Does not apply | 28 |
2.1%
|
| 0 | No obstacle | 129 |
9.6%
|
| 1 | Minor obstacle | 193 |
14.4%
|
| 2 | Moderate obstacle | 289 |
21.6%
|
| 3 | Major obstacle | 308 |
23%
|
| 4 | Very severe obstacle | 349 |
26.1%
|