Table 1. Background information of the blood donors.

Age	Tainan City Blood Center					Kaohsiung City Blood Center
	Male		Female		Subtotal	Male		Female		Subtotal
	n	%	n	%		n	%	n	%
<20	65	2.48	112	8.15	177	33	1.28	75	5.29	108
20–29	512	19.5	467	33.99	979	488	18.91	413	29.11	901
30–39	783	29.82	377	27.44	1,160	790	30.61	385	27.13	1,175
40–49	647	24.64	211	15.36	858	676	26.19	243	17.12	919
50–59	498	18.96	169	12.3	667	465	18.02	237	16.7	702
>60	121	4.61	38	2.77	159	129	5	66	4.65	195
Total	2,626	100	1,374	100	4,000	2,581	100	1,419	100	4,000