| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 15 |
1.6%
|
| 0 | No obstacle | 534 |
58.1%
|
| 1 | Minor obstacle | 200 |
21.8%
|
| 2 | Moderate obstacle | 98 |
10.7%
|
| 3 | Major obstacle | 46 |
5%
|
| 4 | Very severe obstacle | 26 |
2.8%
|