| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.7%
|
| 0 | No obstacle | 36 |
23.8%
|
| 1 | Minor obstacle | 20 |
13.2%
|
| 2 | Moderate obstacle | 53 |
35.1%
|
| 3 | Major obstacle | 34 |
22.5%
|
| 4 | Very severe obstacle | 7 |
4.6%
|