Gender	N	%	Age	N	%
Male	169	45.92	18–24	108	29.35
Female	199	54.08	25–34	163	44.29
			35–44	86	23.37
			45–54	11	2.99

Education	N	%	Annual Income	N	%
High school and lower	19	5.16	RMB 60 K or less	53	14.40
Bachelor’s degree	256	69.57	RMB 60 K–100 K	89	24.18
Master’s degree	78	21.20	RMB 100 K–200 K	124	33.70
PhD degree	15	4.08	RMB 200 K–300 K	67	18.21
			RMB 300 K or more	35	9.51

Length of membership	N	%	Frequency of usage	N	%
Less than 3 months	13	3.53	Rare	15	4.08
3–6 months	22	5.98	Sometimes	73	19.84
6 months–1 year	41	11.14	Fairly frequent	156	42.39
1–2 years	101	27.45	Frequent	81	22.01
Over 2 years	191	51.90	Extremely frequent	43	11.68