| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 22 |
1.4%
|
| -7 | Does not apply | 11 |
0.7%
|
| 0 | No obstacle | 1265 |
80.4%
|
| 1 | Minor obstacle | 150 |
9.5%
|
| 2 | Moderate obstacle | 61 |
3.9%
|
| 3 | Major obstacle | 29 |
1.8%
|
| 4 | Very severe obstacle | 35 |
2.2%
|