| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.2%
|
| -7 | Does not apply | 1 |
0.2%
|
| 0 | No obstacle | 166 |
38.7%
|
| 1 | Minor obstacle | 100 |
23.3%
|
| 2 | Moderate obstacle | 133 |
31%
|
| 3 | Major obstacle | 23 |
5.4%
|
| 4 | Very severe obstacle | 5 |
1.2%
|