| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
2.6%
|
| -7 | Does not apply | 14 |
9.2%
|
| 0 | No obstacle | 95 |
62.5%
|
| 1 | Minor obstacle | 12 |
7.9%
|
| 2 | Moderate obstacle | 13 |
8.6%
|
| 3 | Major obstacle | 9 |
5.9%
|
| 4 | Very severe obstacle | 5 |
3.3%
|