| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 11 |
4.5%
|
| 0 | No obstacle | 108 |
43.9%
|
| 1 | Minor obstacle | 43 |
17.5%
|
| 2 | Moderate obstacle | 34 |
13.8%
|
| 3 | Major obstacle | 35 |
14.2%
|
| 4 | Very severe obstacle | 15 |
6.1%
|