| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.4%
|
| 0 | No obstacle | 80 |
32.5%
|
| 1 | Minor obstacle | 44 |
17.9%
|
| 2 | Moderate obstacle | 65 |
26.4%
|
| 3 | Major obstacle | 37 |
15%
|
| 4 | Very severe obstacle | 19 |
7.7%
|