| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.6%
|
| -7 | Does not apply | 3 |
1.9%
|
| 0 | No obstacle | 129 |
82.2%
|
| 1 | Minor obstacle | 11 |
7%
|
| 2 | Moderate obstacle | 6 |
3.8%
|
| 3 | Major obstacle | 4 |
2.5%
|
| 4 | Very severe obstacle | 3 |
1.9%
|