| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 35 |
100%
|
| -7 | Does not apply | 0 | |
| No obstacle | 0 | ||
| 1 | Minor obstacle | 0 | |
| 2 | Moderate obstacle | 0 | |
| 3 | Major obstacle | 0 | |
| 4 | Very severe obstacle | 0 |