| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 14 |
1%
|
| -7 | Does not apply | 98 |
6.8%
|
| 0 | No obstacle | 914 |
63.2%
|
| 1 | Minor obstacle | 227 |
15.7%
|
| 2 | Moderate obstacle | 119 |
8.2%
|
| 3 | Major obstacle | 43 |
3%
|
| 4 | Very severe obstacle | 31 |
2.1%
|