| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
1.2%
|
| -7 | Does not apply | 11 |
2.6%
|
| 0 | No obstacle | 150 |
35%
|
| 1 | Minor obstacle | 83 |
19.3%
|
| 2 | Moderate obstacle | 155 |
36.1%
|
| 3 | Major obstacle | 17 |
4%
|
| 4 | Very severe obstacle | 8 |
1.9%
|