| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.6%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 17 |
10.8%
|
| 1 | Minor obstacle | 43 |
27.4%
|
| 2 | Moderate obstacle | 56 |
35.7%
|
| 3 | Major obstacle | 30 |
19.1%
|
| 4 | Very severe obstacle | 10 |
6.4%
|