Table 1.

Characteristics of blood donors in different age groups in Shenzhen, 2014–2017

Variables	Aged <25 years (n=95 736), (%)	Aged 25–34 years (n=1 37 447), (%)	Aged 35–44 years (n=102 422), (%)	Aged ≥45 years (n=59 187), (%)	χ2	P value
Gender					11 249.0	<0.001
Male	51 409 (19.3)	96 237 (36.2)	74 445 (28.0)	44 061 (16.6)
Female	44 327 (34.5)	41 210 (32.0)	27 977 (21.7)	15 126 (11.8)
Year of donation					1182.0	<0.001
2014	22 389 (25.3)	31 929 (36.0)	23 131 (26.1)	11 210 (12.6)
2015	24 330 (25.7)	33 096 (35.0)	24 011 (25.4)	13 241 (14.0)
2016	24 560 (24.0)	35 736 (34.9)	26 362 (25.7)	15 843 (15.5)
2017	24 457 (22.4)	36 686 (33.7)	28 918 (26.5)	18 893 (17.3)