| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 9 |
1.2%
|
| -7 | Does not apply | 62 |
8.6%
|
| 0 | No obstacle | 399 |
55.2%
|
| 1 | Minor obstacle | 127 |
17.6%
|
| 2 | Moderate obstacle | 92 |
12.7%
|
| 3 | Major obstacle | 27 |
3.7%
|
| 4 | Very severe obstacle | 7 |
1%
|