| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 4 |
1.9%
|
| 0 | No obstacle | 108 |
50.2%
|
| 1 | Minor obstacle | 58 |
27%
|
| 2 | Moderate obstacle | 26 |
12.1%
|
| 3 | Major obstacle | 14 |
6.5%
|
| 4 | Very severe obstacle | 5 |
2.3%
|