| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 2 |
1.3%
|
| 0 | No obstacle | 75 |
50%
|
| 1 | Minor obstacle | 38 |
25.3%
|
| 2 | Moderate obstacle | 20 |
13.3%
|
| 3 | Major obstacle | 11 |
7.3%
|
| 4 | Very severe obstacle | 4 |
2.7%
|