| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.6%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 25 |
16%
|
| 1 | Minor obstacle | 43 |
27.6%
|
| 2 | Moderate obstacle | 47 |
30.1%
|
| 3 | Major obstacle | 38 |
24.4%
|
| 4 | Very severe obstacle | 2 |
1.3%
|