| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.7%
|
| 0 | No obstacle | 68 |
45.3%
|
| 1 | Minor obstacle | 50 |
33.3%
|
| 2 | Moderate obstacle | 16 |
10.7%
|
| 3 | Major obstacle | 9 |
6%
|
| 4 | Very severe obstacle | 6 |
4%
|