| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 15 |
1%
|
| -7 | Does not apply | 44 |
2.8%
|
| 0 | No obstacle | 1183 |
75.2%
|
| 1 | Minor obstacle | 146 |
9.3%
|
| 2 | Moderate obstacle | 104 |
6.6%
|
| 3 | Major obstacle | 60 |
3.8%
|
| 4 | Very severe obstacle | 21 |
1.3%
|