| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
1.1%
|
| -7 | Does not apply | 50 |
14%
|
| 0 | No obstacle | 126 |
35.3%
|
| 1 | Minor obstacle | 68 |
19%
|
| 2 | Moderate obstacle | 51 |
14.3%
|
| 3 | Major obstacle | 46 |
12.9%
|
| 4 | Very severe obstacle | 12 |
3.4%
|