| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 2 |
0.6%
|
| 0 | No obstacle | 79 |
22.9%
|
| 1 | Minor obstacle | 47 |
13.6%
|
| 2 | Moderate obstacle | 77 |
22.3%
|
| 3 | Major obstacle | 63 |
18.3%
|
| 4 | Very severe obstacle | 77 |
22.3%
|