| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 329 |
54.8%
|
| 1 | Minor obstacle | 166 |
27.7%
|
| 2 | Moderate obstacle | 78 |
13%
|
| 3 | Major obstacle | 19 |
3.2%
|
| 4 | Very severe obstacle | 8 |
1.3%
|