| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.7%
|
| 0 | No obstacle | 110 |
71.9%
|
| 1 | Minor obstacle | 24 |
15.7%
|
| 2 | Moderate obstacle | 12 |
7.8%
|
| 3 | Major obstacle | 6 |
3.9%
|
| 4 | Very severe obstacle | 0 |
0%
|