Table 1. Cohort populations, annual breast cancer mortality from breast cancers diagnosed in 1999–2011, and person-years of exposure in ever- and never-screeneda women aged ⩾45 years, by year of death.

	Ever-screened women			Never-screened women
Year	Number at the beginning of each year	Cumulated person-years exposureb	Breast cancer deaths	Number at the beginning of each year	Cumulated person-years exposureb	Breast cancer deaths
2000	75 562	75 562	5	580 494	580 494	112
2001	154 117	229 612	17	516 246	1 032 492	193
2002	189 075	418 150	27	503 245	1 376 937	244
2003	216 368	633 114	45	492 249	1 696 190	264
2004	240 501	871 106	64	485 611	2 006 453	279
2005	264 539	1 132 195	69	479 766	2 301 812	336
2006	306 023	1 432 983	79	456 778	2 560 596	315
2007	359 385	1 785 670	97	430 703	2  750 229	331
2008	408 896	2 185 630	95	401 855	2 877 408	350
2009	453 086	2  627 404	120	378 058	2 982 745	377
2010	497  697	3 110 437	132	352 890	3 062 181	340
2011	542 234	3 635 261	123	327 623	3 113 051	370
2000-11		3 707 483	873		5 405 518	3511
	Unadjusted 2000–2011 ever-screened : never-screened mortality proportional difference=−63.7%

^aEver or never screened with BreastScreen Aotearoa.

^bAs at the beginning of the year allowing for entry to and exit from cohort.