| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 5 |
1.2%
|
| 0 | No obstacle | 116 |
27%
|
| 1 | Minor obstacle | 57 |
13.3%
|
| 2 | Moderate obstacle | 104 |
24.2%
|
| 3 | Major obstacle | 87 |
20.2%
|
| 4 | Very severe obstacle | 61 |
14.2%
|