| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.3%
|
| 0 | No obstacle | 196 |
54.7%
|
| 1 | Minor obstacle | 68 |
19%
|
| 2 | Moderate obstacle | 54 |
15.1%
|
| 3 | Major obstacle | 30 |
8.4%
|
| 4 | Very severe obstacle | 9 |
2.5%
|