Figure 1From: Secular trends in age at menarche and time to establish regular menstrual cycling in Japanese women born between 1930 and 1985 Box whisker shows the secular changes of mean age at menarche for women born between 1930 and 1985. Heavy line, Median; box, 25-75%; whiskers, 95% confidence interval. * There was significant difference between mean age at menarche born in the 1980s and those born in the 1930s, 1940s and 1950s.Back to article page