| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 2 |
1.3%
|
| 0 | No obstacle | 48 |
31.8%
|
| 1 | Minor obstacle | 52 |
34.4%
|
| 2 | Moderate obstacle | 24 |
15.9%
|
| 3 | Major obstacle | 21 |
13.9%
|
| 4 | Very severe obstacle | 4 |
2.6%
|