| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 16 |
10.2%
|
| 1 | Minor obstacle | 40 |
25.5%
|
| 2 | Moderate obstacle | 57 |
36.3%
|
| 3 | Major obstacle | 28 |
17.8%
|
| 4 | Very severe obstacle | 16 |
10.2%
|