| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.3%
|
| -7 | Does not apply | 2 |
0.6%
|
| 0 | No obstacle | 135 |
37.8%
|
| 1 | Minor obstacle | 101 |
28.3%
|
| 2 | Moderate obstacle | 95 |
26.6%
|
| 3 | Major obstacle | 18 |
5%
|
| 4 | Very severe obstacle | 5 |
1.4%
|