| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 17 |
1.4%
|
| -7 | Does not apply | 5 |
0.4%
|
| 0 | No obstacle | 1071 |
86.4%
|
| 1 | Minor obstacle | 79 |
6.4%
|
| 2 | Moderate obstacle | 45 |
3.6%
|
| 3 | Major obstacle | 17 |
1.4%
|
| 4 | Very severe obstacle | 5 |
0.4%
|