| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.3%
|
| 0 | No obstacle | 65 |
18.8%
|
| 1 | Minor obstacle | 34 |
9.9%
|
| 2 | Moderate obstacle | 100 |
29%
|
| 3 | Major obstacle | 72 |
20.9%
|
| 4 | Very severe obstacle | 73 |
21.2%
|