| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 13 |
1.3%
|
| -7 | Does not apply | 27 |
2.7%
|
| 0 | No obstacle | 374 |
36.9%
|
| 1 | Minor obstacle | 209 |
20.6%
|
| 2 | Moderate obstacle | 174 |
17.2%
|
| 3 | Major obstacle | 148 |
14.6%
|
| 4 | Very severe obstacle | 68 |
6.7%
|