| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 145 |
4.9%
|
| -7 | Does not apply | 90 |
3%
|
| 0 | No obstacle | 1144 |
38.7%
|
| 1 | Minor obstacle | 830 |
28.1%
|
| 2 | Moderate obstacle | 539 |
18.2%
|
| 3 | Major obstacle | 175 |
5.9%
|
| 4 | Very severe obstacle | 32 |
1.1%
|