| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
0.6%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 156 |
21.9%
|
| 1 | Minor obstacle | 109 |
15.3%
|
| 2 | Moderate obstacle | 137 |
19.2%
|
| 3 | Major obstacle | 190 |
26.6%
|
| 4 | Very severe obstacle | 117 |
16.4%
|