| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 4 |
1.1%
|
| 0 | No obstacle | 92 |
25.6%
|
| 1 | Minor obstacle | 42 |
11.7%
|
| 2 | Moderate obstacle | 82 |
22.8%
|
| 3 | Major obstacle | 51 |
14.2%
|
| 4 | Very severe obstacle | 89 |
24.7%
|