| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 106 |
44%
|
| 1 | Minor obstacle | 53 |
22%
|
| 2 | Moderate obstacle | 58 |
24.1%
|
| 3 | Major obstacle | 21 |
8.7%
|
| 4 | Very severe obstacle | 3 |
1.2%
|