| 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 |