| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 11 |
3.1%
|
| -7 | Does not apply | 21 |
5.9%
|
| 0 | No obstacle | 110 |
31.2%
|
| 1 | Minor obstacle | 66 |
18.7%
|
| 2 | Moderate obstacle | 71 |
20.1%
|
| 3 | Major obstacle | 51 |
14.4%
|
| 4 | Very severe obstacle | 23 |
6.5%
|