| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 3 |
2%
|
| 0 | No obstacle | 19 |
12.8%
|
| 1 | Minor obstacle | 48 |
32.2%
|
| 2 | Moderate obstacle | 19 |
12.8%
|
| 3 | Major obstacle | 40 |
26.8%
|
| 4 | Very severe obstacle | 20 |
13.4%
|