| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 8 |
2.2%
|
| -7 | Does not apply | 8 |
2.2%
|
| 0 | No obstacle | 135 |
37.5%
|
| 1 | Minor obstacle | 57 |
15.8%
|
| 2 | Moderate obstacle | 61 |
16.9%
|
| 3 | Major obstacle | 56 |
15.6%
|
| 4 | Very severe obstacle | 35 |
9.7%
|