| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.7%
|
| -7 | Does not apply | 2 |
1.3%
|
| 0 | No obstacle | 76 |
51%
|
| 1 | Minor obstacle | 40 |
26.8%
|
| 2 | Moderate obstacle | 21 |
14.1%
|
| 3 | Major obstacle | 8 |
5.4%
|
| 4 | Very severe obstacle | 1 |
0.7%
|