| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 10 |
2.6%
|
| 0 | No obstacle | 146 |
38.6%
|
| 1 | Minor obstacle | 74 |
19.6%
|
| 2 | Moderate obstacle | 105 |
27.8%
|
| 3 | Major obstacle | 32 |
8.5%
|
| 4 | Very severe obstacle | 11 |
2.9%
|