| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
3.5%
|
| -7 | Does not apply | 11 |
9.6%
|
| 0 | No obstacle | 51 |
44.7%
|
| 1 | Minor obstacle | 27 |
23.7%
|
| 2 | Moderate obstacle | 9 |
7.9%
|
| 3 | Major obstacle | 8 |
7%
|
| 4 | Very severe obstacle | 4 |
3.5%
|