| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 3 |
2.5%
|
| 0 | No obstacle | 43 |
35.8%
|
| 1 | Minor obstacle | 13 |
10.8%
|
| 2 | Moderate obstacle | 32 |
26.7%
|
| 3 | Major obstacle | 18 |
15%
|
| 4 | Very severe obstacle | 11 |
9.2%
|