| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.4%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 91 |
34%
|
| 1 | Minor obstacle | 53 |
19.8%
|
| 2 | Moderate obstacle | 83 |
31%
|
| 3 | Major obstacle | 31 |
11.6%
|
| 4 | Very severe obstacle | 9 |
3.4%
|