| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 2 |
0.8%
|
| 0 | No obstacle | 112 |
44.8%
|
| 1 | Minor obstacle | 57 |
22.8%
|
| 2 | Moderate obstacle | 52 |
20.8%
|
| 3 | Major obstacle | 23 |
9.2%
|
| 4 | Very severe obstacle | 4 |
1.6%
|