| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.8%
|
| -7 | Does not apply | 3 |
0.8%
|
| 0 | No obstacle | 169 |
47.7%
|
| 1 | Minor obstacle | 99 |
28%
|
| 2 | Moderate obstacle | 48 |
13.6%
|
| 3 | Major obstacle | 23 |
6.5%
|
| 4 | Very severe obstacle | 9 |
2.5%
|