| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 |
2%
|
| -7 | Does not apply | 17 |
4.8%
|
| 0 | No obstacle | 169 |
48%
|
| 1 | Minor obstacle | 83 |
23.6%
|
| 2 | Moderate obstacle | 46 |
13.1%
|
| 3 | Major obstacle | 20 |
5.7%
|
| 4 | Very severe obstacle | 10 |
2.8%
|