Table 1.

Characteristics and distribution of unpaid blood donors in recent three years

	Distribution	Total blood donors	Composition ratio (%)
Age (years)	18-24	154,707	58.46
	25-34	42,134	15.92
	35-44	35,162	13.29
	45-55	29,227	11.05
	56-60	3,385	1.28
Gender	Male	169,732	64.14
	Female	94,883	35.86
Educational background	Graduate student	7,746	2.93
	Undergraduate Course	114,903	43.42
	Junior college	81,839	30.93
	High school/Technical secondary school	28,234	10.67
	Junior high school and below	31,893	12.05
Occupation	Worker	2,499	0.94
	Peasant	1,788	0.68
	Student	137,077	51.80
	Soldier	2,328	0.88
	Civil servant	6,151	2.32
	Teacher	3,605	1.36
	Medical personnel	10,760	4.07
	Company staff	31,086	11.75
	Self-employed	2,510	0.95
	Institution staff	2,344	0.89
	Migrant worker	1,560	0.59
	Unknown	62,907	23.77
Blood donation history	The first time	154,855	58.52
	Repeat	109,760	41.48