| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.7%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 74 |
49.3%
|
| 1 | Minor obstacle | 28 |
18.7%
|
| 2 | Moderate obstacle | 24 |
16%
|
| 3 | Major obstacle | 17 |
11.3%
|
| 4 | Very severe obstacle | 6 |
4%
|