| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 2 |
0.3%
|
| 0 | No obstacle | 124 |
20.7%
|
| 1 | Minor obstacle | 112 |
18.7%
|
| 2 | Moderate obstacle | 100 |
16.7%
|
| 3 | Major obstacle | 161 |
26.8%
|
| 4 | Very severe obstacle | 101 |
16.8%
|