| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.8%
|
| -7 | Does not apply | 3 |
2.5%
|
| 0 | No obstacle | 39 |
32.5%
|
| 1 | Minor obstacle | 17 |
14.2%
|
| 2 | Moderate obstacle | 30 |
25%
|
| 3 | Major obstacle | 14 |
11.7%
|
| 4 | Very severe obstacle | 16 |
13.3%
|