| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 1 |
0.2%
|
| 0 | No obstacle | 282 |
46.9%
|
| 1 | Minor obstacle | 154 |
25.6%
|
| 2 | Moderate obstacle | 102 |
17%
|
| 3 | Major obstacle | 52 |
8.7%
|
| 4 | Very severe obstacle | 10 |
1.7%
|