| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.9%
|
| -7 | Does not apply | 4 |
3.5%
|
| 0 | No obstacle | 49 |
43%
|
| 1 | Minor obstacle | 38 |
33.3%
|
| 2 | Moderate obstacle | 15 |
13.2%
|
| 3 | Major obstacle | 5 |
4.4%
|
| 4 | Very severe obstacle | 2 |
1.8%
|