| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.8%
|
| -7 | Does not apply | 2 |
0.8%
|
| 0 | No obstacle | 51 |
19.7%
|
| 1 | Minor obstacle | 44 |
17%
|
| 2 | Moderate obstacle | 69 |
26.6%
|
| 3 | Major obstacle | 58 |
22.4%
|
| 4 | Very severe obstacle | 33 |
12.7%
|