| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 8 |
0.8%
|
| -7 | Does not apply | 11 |
1.1%
|
| 0 | No obstacle | 696 |
69.7%
|
| 1 | Minor obstacle | 177 |
17.7%
|
| 2 | Moderate obstacle | 80 |
8%
|
| 3 | Major obstacle | 19 |
1.9%
|
| 4 | Very severe obstacle | 7 |
0.7%
|