| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.6%
|
| -7 | Does not apply | 4 |
2.6%
|
| 0 | No obstacle | 42 |
26.9%
|
| 1 | Minor obstacle | 24 |
15.4%
|
| 2 | Moderate obstacle | 41 |
26.3%
|
| 3 | Major obstacle | 35 |
22.4%
|
| 4 | Very severe obstacle | 9 |
5.8%
|