| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 32 |
2.6%
|
| -7 | Does not apply | 48 |
3.9%
|
| 0 | No obstacle | 1026 |
82.8%
|
| 1 | Minor obstacle | 37 |
3%
|
| 2 | Moderate obstacle | 45 |
3.6%
|
| 3 | Major obstacle | 30 |
2.4%
|
| 4 | Very severe obstacle | 21 |
1.7%
|