| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.2%
|
| -7 | Does not apply | 3 |
0.6%
|
| 0 | No obstacle | 103 |
20.2%
|
| 1 | Minor obstacle | 203 |
39.7%
|
| 2 | Moderate obstacle | 104 |
20.4%
|
| 3 | Major obstacle | 88 |
17.2%
|
| 4 | Very severe obstacle | 9 |
1.8%
|