| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
1.4%
|
| -7 | Does not apply | 16 |
4.4%
|
| 0 | No obstacle | 208 |
57.6%
|
| 1 | Minor obstacle | 67 |
18.6%
|
| 2 | Moderate obstacle | 34 |
9.4%
|
| 3 | Major obstacle | 17 |
4.7%
|
| 4 | Very severe obstacle | 14 |
3.9%
|