| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
1.4%
|
| -7 | Does not apply | 1 |
0.7%
|
| 0 | No obstacle | 37 |
25.5%
|
| 1 | Minor obstacle | 32 |
22.1%
|
| 2 | Moderate obstacle | 49 |
33.8%
|
| 3 | Major obstacle | 23 |
15.9%
|
| 4 | Very severe obstacle | 1 |
0.7%
|