| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 5 |
1.4%
|
| 0 | No obstacle | 222 |
61%
|
| 1 | Minor obstacle | 40 |
11%
|
| 2 | Moderate obstacle | 46 |
12.6%
|
| 3 | Major obstacle | 21 |
5.8%
|
| 4 | Very severe obstacle | 30 |
8.2%
|