| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 65 |
3.9%
|
| -7 | Does not apply | 53 |
3.2%
|
| 0 | No obstacle | 134 |
8.1%
|
| 1 | Minor obstacle | 123 |
7.4%
|
| 2 | Moderate obstacle | 368 |
22.1%
|
| 3 | Major obstacle | 487 |
29.3%
|
| 4 | Very severe obstacle | 433 |
26%
|