| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 12 |
3.2%
|
| 0 | No obstacle | 183 |
48.8%
|
| 1 | Minor obstacle | 80 |
21.3%
|
| 2 | Moderate obstacle | 75 |
20%
|
| 3 | Major obstacle | 16 |
4.3%
|
| 4 | Very severe obstacle | 9 |
2.4%
|