| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 110 |
6.6%
|
| -7 | Does not apply | 377 |
22.7%
|
| 0 | No obstacle | 317 |
19.1%
|
| 1 | Minor obstacle | 200 |
12%
|
| 2 | Moderate obstacle | 221 |
13.3%
|
| 3 | Major obstacle | 258 |
15.5%
|
| 4 | Very severe obstacle | 180 |
10.8%
|