| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 10 |
1%
|
| -7 | Does not apply | 41 |
4.1%
|
| 0 | No obstacle | 628 |
62.7%
|
| 1 | Minor obstacle | 216 |
21.6%
|
| 2 | Moderate obstacle | 65 |
6.5%
|
| 3 | Major obstacle | 35 |
3.5%
|
| 4 | Very severe obstacle | 7 |
0.7%
|