| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 54 |
0.3%
|
| -7 | Does not apply | 310 |
1.7%
|
| 0 | No obstacle | 10287 |
55.1%
|
| 1 | Minor obstacle | 3985 |
21.4%
|
| 2 | Moderate obstacle | 2458 |
13.2%
|
| 3 | Major obstacle | 1193 |
6.4%
|
| 4 | Very severe obstacle | 370 |
2%
|