| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 31 |
1.2%
|
| -7 | Does not apply | 27 |
1%
|
| 0 | No obstacle | 1171 |
44.4%
|
| 1 | Minor obstacle | 443 |
16.8%
|
| 2 | Moderate obstacle | 584 |
22.2%
|
| 3 | Major obstacle | 293 |
11.1%
|
| 4 | Very severe obstacle | 86 |
3.3%
|