| Value |
Category |
| 1 |
Male |
| 2 |
Female |
| 3 |
Male twins |
| 4 |
Female twins |
| 5 |
Multiple births |
| 6 |
Male-female twin |
| Sysmiss |
|
Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.