| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.6%
|
| -7 | Does not apply | 9 |
2.5%
|
| 0 | No obstacle | 99 |
27.5%
|
| 1 | Minor obstacle | 79 |
21.9%
|
| 2 | Moderate obstacle | 60 |
16.7%
|
| 3 | Major obstacle | 56 |
15.6%
|
| 4 | Very severe obstacle | 55 |
15.3%
|