| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.7%
|
| -7 | Does not apply | 10 |
6.6%
|
| 0 | No obstacle | 77 |
51%
|
| 1 | Minor obstacle | 46 |
30.5%
|
| 2 | Moderate obstacle | 9 |
6%
|
| 3 | Major obstacle | 6 |
4%
|
| 4 | Very severe obstacle | 2 |
1.3%
|