| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.2%
|
| -7 | Does not apply | 10 |
1.7%
|
| 0 | No obstacle | 437 |
75.3%
|
| 1 | Minor obstacle | 37 |
6.4%
|
| 2 | Moderate obstacle | 47 |
8.1%
|
| 3 | Major obstacle | 37 |
6.4%
|
| 4 | Very severe obstacle | 11 |
1.9%
|
| Sysmiss | 1 |