| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
1.3%
|
| -7 | Does not apply | 7 |
2.2%
|
| 0 | No obstacle | 165 |
51.6%
|
| 1 | Minor obstacle | 74 |
23.1%
|
| 2 | Moderate obstacle | 46 |
14.4%
|
| 3 | Major obstacle | 18 |
5.6%
|
| 4 | Very severe obstacle | 6 |
1.9%
|