| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
1.2%
|
| -7 | Does not apply | 35 |
8.7%
|
| 0 | No obstacle | 145 |
36.1%
|
| 1 | Minor obstacle | 62 |
15.4%
|
| 2 | Moderate obstacle | 54 |
13.4%
|
| 3 | Major obstacle | 64 |
15.9%
|
| 4 | Very severe obstacle | 37 |
9.2%
|