| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.4%
|
| -7 | Does not apply | 1 |
0.4%
|
| 0 | No obstacle | 99 |
39.6%
|
| 1 | Minor obstacle | 91 |
36.4%
|
| 2 | Moderate obstacle | 48 |
19.2%
|
| 3 | Major obstacle | 10 |
4%
|
| 4 | Very severe obstacle | 0 |
0%
|