| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 39 |
15.9%
|
| 1 | Minor obstacle | 19 |
7.7%
|
| 2 | Moderate obstacle | 40 |
16.3%
|
| 3 | Major obstacle | 79 |
32.1%
|
| 4 | Very severe obstacle | 69 |
28%
|