| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 4 |
1.6%
|
| 0 | No obstacle | 63 |
25.2%
|
| 1 | Minor obstacle | 99 |
39.6%
|
| 2 | Moderate obstacle | 72 |
28.8%
|
| 3 | Major obstacle | 12 |
4.8%
|
| 4 | Very severe obstacle | 0 |
0%
|