| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.3%
|
| -7 | Does not apply | 4 |
1%
|
| 0 | No obstacle | 89 |
22.7%
|
| 1 | Minor obstacle | 99 |
25.3%
|
| 2 | Moderate obstacle | 101 |
25.8%
|
| 3 | Major obstacle | 79 |
20.2%
|
| 4 | Very severe obstacle | 19 |
4.8%
|