| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 6 |
1.7%
|
| 0 | No obstacle | 146 |
41.4%
|
| 1 | Minor obstacle | 50 |
14.2%
|
| 2 | Moderate obstacle | 49 |
13.9%
|
| 3 | Major obstacle | 68 |
19.3%
|
| 4 | Very severe obstacle | 34 |
9.6%
|