| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 23 |
1.5%
|
| -7 | Does not apply | 149 |
9.5%
|
| 0 | No obstacle | 1007 |
64%
|
| 1 | Minor obstacle | 235 |
14.9%
|
| 2 | Moderate obstacle | 94 |
6%
|
| 3 | Major obstacle | 36 |
2.3%
|
| 4 | Very severe obstacle | 29 |
1.8%
|