| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.3%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 41 |
11.4%
|
| 1 | Minor obstacle | 35 |
9.7%
|
| 2 | Moderate obstacle | 107 |
29.7%
|
| 3 | Major obstacle | 115 |
31.9%
|
| 4 | Very severe obstacle | 61 |
16.9%
|