| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 46 |
4.2%
|
| -7 | Does not apply | 55 |
5%
|
| 0 | No obstacle | 170 |
15.5%
|
| 1 | Minor obstacle | 272 |
24.8%
|
| 2 | Moderate obstacle | 369 |
33.7%
|
| 3 | Major obstacle | 166 |
15.1%
|
| 4 | Very severe obstacle | 18 |
1.6%
|