| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 8 |
2.6%
|
| -7 | Does not apply | 2 |
0.7%
|
| 0 | No obstacle | 135 |
44%
|
| 1 | Minor obstacle | 58 |
18.9%
|
| 2 | Moderate obstacle | 38 |
12.4%
|
| 3 | Major obstacle | 44 |
14.3%
|
| 4 | Very severe obstacle | 22 |
7.2%
|