| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 78 |
7.8%
|
| 0 | No obstacle | 681 |
68.2%
|
| 1 | Minor obstacle | 151 |
15.1%
|
| 2 | Moderate obstacle | 57 |
5.7%
|
| 3 | Major obstacle | 22 |
2.2%
|
| 4 | Very severe obstacle | 9 |
0.9%
|