| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.5%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 56 |
25.6%
|
| 1 | Minor obstacle | 38 |
17.4%
|
| 2 | Moderate obstacle | 43 |
19.6%
|
| 3 | Major obstacle | 41 |
18.7%
|
| 4 | Very severe obstacle | 40 |
18.3%
|