| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 13 |
5%
|
| -7 | Does not apply | 21 |
8.1%
|
| 0 | No obstacle | 132 |
51%
|
| 1 | Minor obstacle | 45 |
17.4%
|
| 2 | Moderate obstacle | 27 |
10.4%
|
| 3 | Major obstacle | 14 |
5.4%
|
| 4 | Very severe obstacle | 7 |
2.7%
|