| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
1%
|
| -7 | Does not apply | 5 |
1.2%
|
| 0 | No obstacle | 100 |
24.9%
|
| 1 | Minor obstacle | 119 |
29.6%
|
| 2 | Moderate obstacle | 53 |
13.2%
|
| 3 | Major obstacle | 66 |
16.4%
|
| 4 | Very severe obstacle | 55 |
13.7%
|