| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 11 |
1.5%
|
| -7 | Does not apply | 16 |
2.2%
|
| 0 | No obstacle | 510 |
70%
|
| 1 | Minor obstacle | 75 |
10.3%
|
| 2 | Moderate obstacle | 58 |
8%
|
| 3 | Major obstacle | 22 |
3%
|
| 4 | Very severe obstacle | 37 |
5.1%
|