| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
1.1%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 73 |
20%
|
| 1 | Minor obstacle | 80 |
21.9%
|
| 2 | Moderate obstacle | 113 |
31%
|
| 3 | Major obstacle | 82 |
22.5%
|
| 4 | Very severe obstacle | 13 |
3.6%
|