| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.5%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 89 |
40.6%
|
| 1 | Minor obstacle | 42 |
19.2%
|
| 2 | Moderate obstacle | 57 |
26%
|
| 3 | Major obstacle | 17 |
7.8%
|
| 4 | Very severe obstacle | 13 |
5.9%
|