| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.3%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 131 |
36.2%
|
| 1 | Minor obstacle | 66 |
18.2%
|
| 2 | Moderate obstacle | 78 |
21.5%
|
| 3 | Major obstacle | 59 |
16.3%
|
| 4 | Very severe obstacle | 27 |
7.5%
|