| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 13 |
3.6%
|
| -7 | Does not apply | 2 |
0.6%
|
| 0 | No obstacle | 95 |
26.5%
|
| 1 | Minor obstacle | 90 |
25.1%
|
| 2 | Moderate obstacle | 101 |
28.2%
|
| 3 | Major obstacle | 47 |
13.1%
|
| 4 | Very severe obstacle | 10 |
2.8%
|