| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 12 |
0.8%
|
| -7 | Does not apply | 69 |
4.8%
|
| 0 | No obstacle | 989 |
68.4%
|
| 1 | Minor obstacle | 206 |
14.2%
|
| 2 | Moderate obstacle | 123 |
8.5%
|
| 3 | Major obstacle | 30 |
2.1%
|
| 4 | Very severe obstacle | 17 |
1.2%
|