| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 47 |
4.3%
|
| -7 | Does not apply | 30 |
2.7%
|
| 0 | No obstacle | 71 |
6.5%
|
| 1 | Minor obstacle | 201 |
18.3%
|
| 2 | Moderate obstacle | 349 |
31.8%
|
| 3 | Major obstacle | 288 |
26.3%
|
| 4 | Very severe obstacle | 110 |
10%
|