| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 35 |
2.4%
|
| -7 | Does not apply | 61 |
4.3%
|
| 0 | No obstacle | 1107 |
77.3%
|
| 1 | Minor obstacle | 114 |
8%
|
| 2 | Moderate obstacle | 66 |
4.6%
|
| 3 | Major obstacle | 34 |
2.4%
|
| 4 | Very severe obstacle | 15 |
1%
|