| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 56 |
2.8%
|
| -7 | Does not apply | 62 |
3.1%
|
| 0 | No obstacle | 1556 |
78%
|
| 1 | Minor obstacle | 94 |
4.7%
|
| 2 | Moderate obstacle | 102 |
5.1%
|
| 3 | Major obstacle | 98 |
4.9%
|
| 4 | Very severe obstacle | 27 |
1.4%
|