| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.3%
|
| 0 | No obstacle | 93 |
25.8%
|
| 1 | Minor obstacle | 126 |
35%
|
| 2 | Moderate obstacle | 91 |
25.3%
|
| 3 | Major obstacle | 39 |
10.8%
|
| 4 | Very severe obstacle | 10 |
2.8%
|