| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.1%
|
| -7 | Does not apply (spontaneous) | 46 |
2.9%
|
| 0 | No obstacle | 1423 |
90.5%
|
| 1 | Minor obstacle | 69 |
4.4%
|
| 2 | Moderate obstacle | 16 |
1%
|
| 3 | Major obstacle | 13 |
0.8%
|
| 4 | Very severe obstacle | 4 |
0.3%
|