| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.5%
|
| -7 | Does not apply | 3 |
1.4%
|
| 0 | No obstacle | 44 |
21.1%
|
| 1 | Minor obstacle | 82 |
39.2%
|
| 2 | Moderate obstacle | 38 |
18.2%
|
| 3 | Major obstacle | 34 |
16.3%
|
| 4 | Very severe obstacle | 7 |
3.3%
|