| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 9 |
0.9%
|
| 0 | No obstacle | 723 |
70.6%
|
| 1 | Minor obstacle | 185 |
18.1%
|
| 2 | Moderate obstacle | 62 |
6.1%
|
| 3 | Major obstacle | 40 |
3.9%
|
| 4 | Very severe obstacle | 5 |
0.5%
|