| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 6 |
1.2%
|
| 0 | No obstacle | 56 |
11%
|
| 1 | Minor obstacle | 142 |
27.8%
|
| 2 | Moderate obstacle | 86 |
16.8%
|
| 3 | Major obstacle | 158 |
30.9%
|
| 4 | Very severe obstacle | 63 |
12.3%
|