| Value | Category | Cases | |
|---|---|---|---|
| -97 | Don't know | 22 |
9.2%
|
| 1 | 20cm | 171 |
71.5%
|
| 2 | 30cm | 31 |
13%
|
| 3 | 40cm | 8 |
3.3%
|
| 4 | 50cm | 7 |
2.9%
|
| a | Not applicable | 0 | |
| b | Don't know | 0 | |
| c | Refused to respond | 0 |