| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 33 |
3.3%
|
| -7 | Does not apply | 26 |
2.6%
|
| 0 | No obstacle | 563 |
55.9%
|
| 1 | Minor obstacle | 204 |
20.2%
|
| 2 | Moderate obstacle | 86 |
8.5%
|
| 3 | Major obstacle | 76 |
7.5%
|
| 4 | Very severe obstacle | 20 |
2%
|