| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 2 |
0.6%
|
| 0 | No obstacle | 202 |
56.1%
|
| 1 | Minor obstacle | 68 |
18.9%
|
| 2 | Moderate obstacle | 62 |
17.2%
|
| 3 | Major obstacle | 24 |
6.7%
|
| 4 | Very severe obstacle | 2 |
0.6%
|