| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 13 |
0.7%
|
| -7 | Does not apply | 27 |
1.4%
|
| 0 | No obstacle | 1486 |
74.5%
|
| 1 | Minor obstacle | 191 |
9.6%
|
| 2 | Moderate obstacle | 156 |
7.8%
|
| 3 | Major obstacle | 74 |
3.7%
|
| 4 | Very severe obstacle | 48 |
2.4%
|