| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 11 |
1.1%
|
| 0 | No obstacle | 750 |
73.2%
|
| 1 | Minor obstacle | 151 |
14.7%
|
| 2 | Moderate obstacle | 46 |
4.5%
|
| 3 | Major obstacle | 48 |
4.7%
|
| 4 | Very severe obstacle | 18 |
1.8%
|