| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 264 |
45.4%
|
| 1 | Minor obstacle | 134 |
23%
|
| 2 | Moderate obstacle | 102 |
17.5%
|
| 3 | Major obstacle | 63 |
10.8%
|
| 4 | Very severe obstacle | 19 |
3.3%
|