| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 |
0.9%
|
| -7 | Does not apply | 23 |
3%
|
| 0 | No obstacle | 233 |
30.7%
|
| 1 | Minor obstacle | 164 |
21.6%
|
| 2 | Moderate obstacle | 218 |
28.7%
|
| 3 | Major obstacle | 67 |
8.8%
|
| 4 | Very severe obstacle | 48 |
6.3%
|