| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 273 |
44.4%
|
| 1 | Minor obstacle | 156 |
25.4%
|
| 2 | Moderate obstacle | 119 |
19.3%
|
| 3 | Major obstacle | 58 |
9.4%
|
| 4 | Very severe obstacle | 9 |
1.5%
|