| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 |
4.1%
|
| -7 | Does not apply | 5 |
3.4%
|
| 0 | No obstacle | 57 |
38.5%
|
| 1 | Minor obstacle | 38 |
25.7%
|
| 2 | Moderate obstacle | 19 |
12.8%
|
| 3 | Major obstacle | 15 |
10.1%
|
| 4 | Very severe obstacle | 8 |
5.4%
|