| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 12 |
2%
|
| 0 | No obstacle | 283 |
47.1%
|
| 1 | Minor obstacle | 148 |
24.6%
|
| 2 | Moderate obstacle | 65 |
10.8%
|
| 3 | Major obstacle | 53 |
8.8%
|
| 4 | Very severe obstacle | 40 |
6.7%
|