| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 44 |
5.7%
|
| -7 | Does not apply | 29 |
3.8%
|
| 0 | No obstacle | 232 |
30.1%
|
| 1 | Minor obstacle | 148 |
19.2%
|
| 2 | Moderate obstacle | 151 |
19.6%
|
| 3 | Major obstacle | 109 |
14.1%
|
| 4 | Very severe obstacle | 59 |
7.6%
|