| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 5 |
1.2%
|
| 0 | No obstacle | 111 |
27.6%
|
| 1 | Minor obstacle | 79 |
19.7%
|
| 2 | Moderate obstacle | 109 |
27.1%
|
| 3 | Major obstacle | 81 |
20.1%
|
| 4 | Very severe obstacle | 17 |
4.2%
|