| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 50 |
2.5%
|
| -7 | Does not apply | 69 |
3.5%
|
| 0 | No obstacle | 1444 |
72.4%
|
| 1 | Minor obstacle | 113 |
5.7%
|
| 2 | Moderate obstacle | 116 |
5.8%
|
| 3 | Major obstacle | 135 |
6.8%
|
| 4 | Very severe obstacle | 68 |
3.4%
|