| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 81 |
16.9%
|
| 1 | Minor obstacle | 137 |
28.5%
|
| 2 | Moderate obstacle | 132 |
27.5%
|
| 3 | Major obstacle | 77 |
16%
|
| 4 | Very severe obstacle | 53 |
11%
|