| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 418 |
69.7%
|
| 1 | Minor obstacle | 138 |
23%
|
| 2 | Moderate obstacle | 33 |
5.5%
|
| 3 | Major obstacle | 8 |
1.3%
|
| 4 | Very severe obstacle | 3 |
0.5%
|