| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | |
| -7 | Does not apply | 0 | |
| 0 | No obstacle | 12 |
3.3%
|
| 1 | Minor obstacle | 54 |
15%
|
| 2 | Moderate obstacle | 87 |
24.2%
|
| 3 | Major obstacle | 128 |
35.6%
|
| 4 | Very severe obstacle | 79 |
21.9%
|