| Value | Category |
|---|---|
| 1 | Difference in age between respondent and sibling 1 |
| 2 | Difference in age between respondent and sibling 2 |
| 3 | Difference in age between respondent and sibling 3 |
| 4 | Difference in age between respondent and sibling 4 |
| 5 | Difference in age between respondent and sibling 5 |
| 6 | Difference in age between respondent and sibling 6 |
| 7 | Difference in age between respondent and sibling 7 |
| 8 | Difference in age between respondent and sibling 8 |