| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.6%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 31 |
19.9%
|
| 1 | Minor obstacle | 50 |
32.1%
|
| 2 | Moderate obstacle | 54 |
34.6%
|
| 3 | Major obstacle | 16 |
10.3%
|
| 4 | Very severe obstacle | 4 |
2.6%
|