TABLE 2.

Descriptive statistics of respondent characteristics.

Statistical indicator	Category	Frequency	Effective percentage (%)
Gender	Male	540	45.92
	Female	636	54.08
Age (year)	18–25	552	46.94
	26–35	381	32.40
	36–45	117	9.95
	46–55	81	6.89
	56–65	39	3.31
	66–72	6	0.51
Family size	1	75	6.38
	2	180	15.31
	3	436	37.07
	4	246	20.92
	5	239	20.32
Level of education	Primary school and below	86	7.31
	Senior high school (including technical secondary school)	191	16.24
	College	255	21.68
	University	537	45.67
	Postgraduate and above	107	9.10
Annual household income	≤ 50000 Yuan	81	6.89
	50001–80000 Yuan	187	15.90
	80001–100000 Yuan	237	20.15
	100001–150000 Yuan	215	18.28
	>150000 Yuan	456	38.78