| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 6 |
5.3%
|
| 0 | No obstacle | 52 |
45.6%
|
| 1 | Minor obstacle | 30 |
26.3%
|
| 2 | Moderate obstacle | 18 |
15.8%
|
| 3 | Major obstacle | 5 |
4.4%
|
| 4 | Very severe obstacle | 3 |
2.6%
|