| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 11 |
0.8%
|
| -7 | Does not apply | 56 |
3.9%
|
| 0 | No obstacle | 943 |
65.2%
|
| 1 | Minor obstacle | 243 |
16.8%
|
| 2 | Moderate obstacle | 149 |
10.3%
|
| 3 | Major obstacle | 30 |
2.1%
|
| 4 | Very severe obstacle | 14 |
1%
|