Age-specific breast cancer rates and 95% confidence intervals by mammogram history. Data for the Mammography Evaluation Cohort are from the Norwegian Women and Cancer Study, 2005–2010. The control group includes women who reported never having had a mammogram, and women who only had mammograms outside the screening program. Vertical lines separate prevalence screening (ages 50–51), incidence screening (ages 52–69), and follow-up (ages 70–79). The rates for ages 50–51 are from Falk et al. . The last age category includes 10 years due to small numbers.