| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.9%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 56 |
49.1%
|
| 1 | Minor obstacle | 32 |
28.1%
|
| 2 | Moderate obstacle | 11 |
9.6%
|
| 3 | Major obstacle | 9 |
7.9%
|
| 4 | Very severe obstacle | 5 |
4.4%
|