| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.7%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 259 |
64.1%
|
| 1 | Minor obstacle | 38 |
9.4%
|
| 2 | Moderate obstacle | 50 |
12.4%
|
| 3 | Major obstacle | 30 |
7.4%
|
| 4 | Very severe obstacle | 24 |
5.9%
|