| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.8%
|
| -7 | Does not apply | 4 |
1.1%
|
| 0 | No obstacle | 71 |
19.5%
|
| 1 | Minor obstacle | 130 |
35.6%
|
| 2 | Moderate obstacle | 95 |
26%
|
| 3 | Major obstacle | 48 |
13.2%
|
| 4 | Very severe obstacle | 14 |
3.8%
|