| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 22 |
14.9%
|
| 0 | No obstacle | 16 |
10.8%
|
| 1 | Minor obstacle | 33 |
22.3%
|
| 2 | Moderate obstacle | 18 |
12.2%
|
| 3 | Major obstacle | 27 |
18.2%
|
| 4 | Very severe obstacle | 32 |
21.6%
|