| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 14 |
1.4%
|
| -7 | Does not apply | 8 |
0.8%
|
| 0 | No obstacle | 424 |
42.3%
|
| 1 | Minor obstacle | 262 |
26.1%
|
| 2 | Moderate obstacle | 155 |
15.5%
|
| 3 | Major obstacle | 106 |
10.6%
|
| 4 | Very severe obstacle | 33 |
3.3%
|