| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.3%
|
| -7 | Does not apply | 6 |
1.7%
|
| 0 | No obstacle | 70 |
19.8%
|
| 1 | Minor obstacle | 56 |
15.9%
|
| 2 | Moderate obstacle | 46 |
13%
|
| 3 | Major obstacle | 79 |
22.4%
|
| 4 | Very severe obstacle | 95 |
26.9%
|