Table 1.

Encodings, means, and notes of variables.

Variables	Category	Frequency	Percentage (%)	Note
Gender	Male	26,974	77.9
	Female	7,662	22.1
Age				Mean = 49.29
				Standard Deviation = 15.46
Ethnics	Han-nationality	32,889	95.0
	Others	1,747	5.0
Education	Illiteracy	1,416	4.1
	Primary school	7,695	22.2
	Middle school	12,019	34.7
	High school	6,779	19.6
	University	6,483	18.7
Marital status	being married	14,200	41.2
	Single/divorced/widowed		58.8
Period	1995-2020			6 periods
Cohort				13 cohort groups