| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 12 |
1.1%
|
| -7 | Does not apply | 58 |
5.3%
|
| 0 | No obstacle | 664 |
61.1%
|
| 1 | Minor obstacle | 137 |
12.6%
|
| 2 | Moderate obstacle | 118 |
10.9%
|
| 3 | Major obstacle | 67 |
6.2%
|
| 4 | Very severe obstacle | 30 |
2.8%
|