| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 8 |
1.2%
|
| 0 | No obstacle | 117 |
18%
|
| 1 | Minor obstacle | 68 |
10.5%
|
| 2 | Moderate obstacle | 70 |
10.8%
|
| 3 | Major obstacle | 110 |
16.9%
|
| 4 | Very severe obstacle | 276 |
42.5%
|