| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.6%
|
| -7 | Does not apply | 6 |
1.7%
|
| 0 | No obstacle | 131 |
36.4%
|
| 1 | Minor obstacle | 78 |
21.7%
|
| 2 | Moderate obstacle | 80 |
22.2%
|
| 3 | Major obstacle | 54 |
15%
|
| 4 | Very severe obstacle | 9 |
2.5%
|