| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 40 |
3.9%
|
| -7 | Does not apply | 82 |
8%
|
| 0 | No obstacle | 571 |
55.5%
|
| 1 | Minor obstacle | 152 |
14.8%
|
| 2 | Moderate obstacle | 107 |
10.4%
|
| 3 | Major obstacle | 65 |
6.3%
|
| 4 | Very severe obstacle | 11 |
1.1%
|