BIRTHY1 is a 4-digit-numeric variable.
0: Not in universe
9998: Unknown-not ascertained
9999: Unknown-don't know
For female sample persons aged 18 and older who have ever had a live birth and do not remember how old they were when the first child was born, BIRTHY1 reports the year in which the sample person's first child was born.
- 2000; 2005; 2010; 2015: Female sample adults age 18+ who ever had a live birth and do not remember how old they were when first child was born.
- 2000, 2005, 2010, 2015
- 2000, 2005, 2010, 2015 : SAMPWEIGHT