| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 189 |
52.1%
|
| 1 | Minor obstacle | 80 |
22%
|
| 2 | Moderate obstacle | 49 |
13.5%
|
| 3 | Major obstacle | 27 |
7.4%
|
| 4 | Very severe obstacle | 18 |
5%
|