| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 285 |
79.2%
|
| 1 | Minor obstacle | 36 |
10%
|
| 2 | Moderate obstacle | 30 |
8.3%
|
| 3 | Major obstacle | 7 |
1.9%
|
| 4 | Very severe obstacle | 2 |
0.6%
|