| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.3%
|
| 0 | No obstacle | 100 |
25.5%
|
| 1 | Minor obstacle | 89 |
22.7%
|
| 2 | Moderate obstacle | 97 |
24.7%
|
| 3 | Major obstacle | 82 |
20.9%
|
| 4 | Very severe obstacle | 23 |
5.9%
|