| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.6%
|
| -7 | Does not apply | 3 |
0.9%
|
| 0 | No obstacle | 177 |
55.3%
|
| 1 | Minor obstacle | 66 |
20.6%
|
| 2 | Moderate obstacle | 45 |
14.1%
|
| 3 | Major obstacle | 20 |
6.3%
|
| 4 | Very severe obstacle | 7 |
2.2%
|