| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.4%
|
| -7 | Does not apply | 13 |
2.5%
|
| 0 | No obstacle | 227 |
44.4%
|
| 1 | Minor obstacle | 121 |
23.7%
|
| 2 | Moderate obstacle | 83 |
16.2%
|
| 3 | Major obstacle | 51 |
10%
|
| 4 | Very severe obstacle | 14 |
2.7%
|