| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 35 |
22.3%
|
| 1 | Minor obstacle | 55 |
35%
|
| 2 | Moderate obstacle | 44 |
28%
|
| 3 | Major obstacle | 15 |
9.6%
|
| 4 | Very severe obstacle | 8 |
5.1%
|