| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.4%
|
| 0 | No obstacle | 97 |
40.4%
|
| 1 | Minor obstacle | 26 |
10.8%
|
| 2 | Moderate obstacle | 18 |
7.5%
|
| 3 | Major obstacle | 35 |
14.6%
|
| 4 | Very severe obstacle | 63 |
26.3%
|