| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 12 |
1.2%
|
| -7 | Does not apply | 52 |
5.2%
|
| 0 | No obstacle | 483 |
48.3%
|
| 1 | Minor obstacle | 251 |
25.1%
|
| 2 | Moderate obstacle | 101 |
10.1%
|
| 3 | Major obstacle | 83 |
8.3%
|
| 4 | Very severe obstacle | 19 |
1.9%
|