| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.9%
|
| -7 | Does not apply | 20 |
8.6%
|
| 0 | No obstacle | 183 |
78.5%
|
| 1 | Minor obstacle | 14 |
6%
|
| 2 | Moderate obstacle | 6 |
2.6%
|
| 3 | Major obstacle | 6 |
2.6%
|
| 4 | Very severe obstacle | 2 |
0.9%
|