| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 149 |
5%
|
| -7 | Does not apply | 88 |
3%
|
| 0 | No obstacle | 1081 |
36.6%
|
| 1 | Minor obstacle | 823 |
27.9%
|
| 2 | Moderate obstacle | 619 |
20.9%
|
| 3 | Major obstacle | 166 |
5.6%
|
| 4 | Very severe obstacle | 29 |
1%
|