| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 14 |
1.4%
|
| -7 | Does not apply | 41 |
4%
|
| 0 | No obstacle | 739 |
71.9%
|
| 1 | Minor obstacle | 148 |
14.4%
|
| 2 | Moderate obstacle | 51 |
5%
|
| 3 | Major obstacle | 32 |
3.1%
|
| 4 | Very severe obstacle | 3 |
0.3%
|