| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 221 |
30.3%
|
| 1 | Minor obstacle | 105 |
14.4%
|
| 2 | Moderate obstacle | 83 |
11.4%
|
| 3 | Major obstacle | 110 |
15.1%
|
| 4 | Very severe obstacle | 210 |
28.8%
|