| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 9 |
0.9%
|
| -7 | Does not apply | 16 |
1.6%
|
| 0 | No obstacle | 555 |
55.4%
|
| 1 | Minor obstacle | 245 |
24.5%
|
| 2 | Moderate obstacle | 90 |
9%
|
| 3 | Major obstacle | 54 |
5.4%
|
| 4 | Very severe obstacle | 33 |
3.3%
|