| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.8%
|
| -7 | Does not apply | 22 |
9.2%
|
| 0 | No obstacle | 142 |
59.2%
|
| 1 | Minor obstacle | 36 |
15%
|
| 2 | Moderate obstacle | 26 |
10.8%
|
| 3 | Major obstacle | 7 |
2.9%
|
| 4 | Very severe obstacle | 5 |
2.1%
|