| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 18 |
1.2%
|
| -7 | Does not apply | 77 |
5.3%
|
| 0 | No obstacle | 797 |
55.1%
|
| 1 | Minor obstacle | 223 |
15.4%
|
| 2 | Moderate obstacle | 178 |
12.3%
|
| 3 | Major obstacle | 94 |
6.5%
|
| 4 | Very severe obstacle | 59 |
4.1%
|