| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 18 |
12.4%
|
| 1 | Minor obstacle | 25 |
17.2%
|
| 2 | Moderate obstacle | 36 |
24.8%
|
| 3 | Major obstacle | 51 |
35.2%
|
| 4 | Very severe obstacle | 15 |
10.3%
|