| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.6%
|
| -7 | Does not apply | 3 |
0.8%
|
| 0 | No obstacle | 109 |
30.3%
|
| 1 | Minor obstacle | 43 |
11.9%
|
| 2 | Moderate obstacle | 72 |
20%
|
| 3 | Major obstacle | 61 |
16.9%
|
| 4 | Very severe obstacle | 70 |
19.4%
|