| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.8%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 206 |
57.1%
|
| 1 | Minor obstacle | 63 |
17.5%
|
| 2 | Moderate obstacle | 62 |
17.2%
|
| 3 | Major obstacle | 18 |
5%
|
| 4 | Very severe obstacle | 9 |
2.5%
|