| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.3%
|
| -7 | Does not apply | 0 |
0%
|
| 0 | No obstacle | 111 |
28.6%
|
| 1 | Minor obstacle | 115 |
29.6%
|
| 2 | Moderate obstacle | 117 |
30.2%
|
| 3 | Major obstacle | 27 |
7%
|
| 4 | Very severe obstacle | 17 |
4.4%
|