| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0%
|
| -7 | Does not apply | 15 |
0.6%
|
| 0 | No obstacle | 791 |
30%
|
| 1 | Minor obstacle | 582 |
22.1%
|
| 2 | Moderate obstacle | 722 |
27.4%
|
| 3 | Major obstacle | 359 |
13.6%
|
| 4 | Very severe obstacle | 165 |
6.3%
|