| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.9%
|
| 0 | No obstacle | 48 |
43.2%
|
| 1 | Minor obstacle | 30 |
27%
|
| 2 | Moderate obstacle | 21 |
18.9%
|
| 3 | Major obstacle | 7 |
6.3%
|
| 4 | Very severe obstacle | 4 |
3.6%
|