| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
1.3%
|
| -7 | Does not apply | 1 |
0.7%
|
| 0 | No obstacle | 92 |
61.7%
|
| 1 | Minor obstacle | 38 |
25.5%
|
| 2 | Moderate obstacle | 14 |
9.4%
|
| 3 | Major obstacle | 2 |
1.3%
|
| 4 | Very severe obstacle | 0 |
0%
|