| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 19 |
1.9%
|
| -7 | Does not apply | 9 |
0.9%
|
| 0 | No obstacle | 618 |
61.3%
|
| 1 | Minor obstacle | 195 |
19.3%
|
| 2 | Moderate obstacle | 68 |
6.7%
|
| 3 | Major obstacle | 74 |
7.3%
|
| 4 | Very severe obstacle | 25 |
2.5%
|