| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 12 |
0.8%
|
| -7 | Does not apply | 71 |
4.9%
|
| 0 | No obstacle | 809 |
55.9%
|
| 1 | Minor obstacle | 219 |
15.1%
|
| 2 | Moderate obstacle | 207 |
14.3%
|
| 3 | Major obstacle | 86 |
5.9%
|
| 4 | Very severe obstacle | 42 |
2.9%
|