| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.3%
|
| 0 | No obstacle | 186 |
51.1%
|
| 1 | Minor obstacle | 54 |
14.8%
|
| 2 | Moderate obstacle | 83 |
22.8%
|
| 3 | Major obstacle | 29 |
8%
|
| 4 | Very severe obstacle | 11 |
3%
|