Table 1. Characteristics of the study participants in the Guangdong province of South China during 2014–2015.

Characteristics	Category	Frequency	Percentage
Age (years)	0–12	16188	11.63
	13–22	2904	2.08
	23–59	69026	49.58
	60+	51103	36.71
Gender	Male	53718	31.75
	Female	115493	68.25
Height (cm)	<155	70051	44.17
	155–159	34533	21.77
	160–164	25936	16.35
	≥165	28071	17.70
BMI (kg/m2)	<18.5	16104	10.18
	18.5 to <22.5	71553	45.23
	22.5 to <25	51934	32.83
	25 to <30	15758	9.96
	≥30	2849	1.80
Nationality	Han	164425	97.66
	Minority	3946	2.34
Educational level	Illiteracy	7305	4.87
	Primary school	56573	37.68
	Middle school	40384	26.90
	High and vocational school	34681	23.10
	Undergraduate and above	11208	7.46
Career	Leaders of enterprise unit	2272	1.50
	Technical personnel	4508	2.98
	Handle affairs personnel	3851	2.55
	Commercial personnel	6885	4.55
	Agricultural, forestry and fishery producers	25948	17.16
	Transportation equipment operators	7553	5.00
	Others	100179	66.26
Marital status	Single	24254	15.77
	Married	120380	78.27
	Widowed	7719	5.02
	Divorced	1451	0.94
Hepatitis B vaccination (aged 0–22 years)	Yes	5457	90.63
	No	564	9.37
Hepatitis B vaccination (aged 23–59 years)	Yes	1886	17.71
	No	8763	82.29
Hepatitis B vaccination (aged 60+ years)	Yes	6997	13.70
	No	44082	86.30

Two basic descriptive statistics including the frequency and percentage were used.