| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 8 |
0.8%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 603 |
59.8%
|
| 1 | Minor obstacle | 272 |
27%
|
| 2 | Moderate obstacle | 100 |
9.9%
|
| 3 | Major obstacle | 19 |
1.9%
|
| 4 | Very severe obstacle | 6 |
0.6%
|