| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 20 |
8.3%
|
| 1 | Minor obstacle | 26 |
10.8%
|
| 2 | Moderate obstacle | 56 |
23.2%
|
| 3 | Major obstacle | 98 |
40.7%
|
| 4 | Very severe obstacle | 41 |
17%
|