| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 150 |
5.1%
|
| -7 | Does not apply | 316 |
10.7%
|
| 0 | No obstacle | 962 |
32.6%
|
| 1 | Minor obstacle | 428 |
14.5%
|
| 2 | Moderate obstacle | 529 |
17.9%
|
| 3 | Major obstacle | 400 |
13.5%
|
| 4 | Very severe obstacle | 170 |
5.8%
|