| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 8 |
5.1%
|
| -7 | Does not apply | 26 |
16.6%
|
| 0 | No obstacle | 109 |
69.4%
|
| 1 | Minor obstacle | 9 |
5.7%
|
| 2 | Moderate obstacle | 4 |
2.5%
|
| 3 | Major obstacle | 0 |
0%
|
| 4 | Very severe obstacle | 1 |
0.6%
|