| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 2 |
1.7%
|
| 0 | No obstacle | 57 |
47.5%
|
| 1 | Minor obstacle | 15 |
12.5%
|
| 2 | Moderate obstacle | 33 |
27.5%
|
| 3 | Major obstacle | 9 |
7.5%
|
| 4 | Very severe obstacle | 4 |
3.3%
|