| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.5%
|
| 0 | No obstacle | 24 |
11.5%
|
| 1 | Minor obstacle | 93 |
44.5%
|
| 2 | Moderate obstacle | 25 |
12%
|
| 3 | Major obstacle | 46 |
22%
|
| 4 | Very severe obstacle | 20 |
9.6%
|