Characteristics		n	%
Age group (years)	<30	46	12.0
	30 - 39	180	47.0
	>39	157	41.0
Education level	College or above	311	81.2
Education level	High school or below	72	18.8
Income (a person per month)	Low (<5000)	133	34.7
	Moderate (5000 - 8000)	114	29.8
	High (>8000)	136	35.5
Residence	Urban	327	85.4
Residence	Rural	56	14.6
Only child	Yes	105	27.4
Only child	No	278	72.6
Marital status	Unmarried	47	12.3
	Married	309	80.7
	Divorced or widowed	27	7.0
Spouse’s education level	College or above	259	77.1
Spouse’s education level	High school or below	77	22.9
Conjugal relationship	Not close	43	12.8
	Relatively close	172	51.2
	Very close	121	36.0
Gender of the first child	Male	163	50.6
Gender of the first child	Female	159	49.4