| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.6%
|
| 0 | No obstacle | 76 |
43.9%
|
| 1 | Minor obstacle | 22 |
12.7%
|
| 2 | Moderate obstacle | 19 |
11%
|
| 3 | Major obstacle | 16 |
9.2%
|
| 4 | Very severe obstacle | 39 |
22.5%
|