| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 10 |
0.7%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 599 |
42.3%
|
| 1 | Minor obstacle | 296 |
20.9%
|
| 2 | Moderate obstacle | 200 |
14.1%
|
| 3 | Major obstacle | 149 |
10.5%
|
| 4 | Very severe obstacle | 162 |
11.4%
|