| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 5 |
1%
|
| 0 | No obstacle | 290 |
57.8%
|
| 1 | Minor obstacle | 92 |
18.3%
|
| 2 | Moderate obstacle | 71 |
14.1%
|
| 3 | Major obstacle | 35 |
7%
|
| 4 | Very severe obstacle | 9 |
1.8%
|