| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 58 |
8%
|
| 0 | No obstacle | 149 |
20.6%
|
| 1 | Minor obstacle | 75 |
10.4%
|
| 2 | Moderate obstacle | 130 |
18%
|
| 3 | Major obstacle | 150 |
20.7%
|
| 4 | Very severe obstacle | 161 |
22.3%
|