The Washington Post has created a series of interactive visualizations showing demographic information for the world’s population. One visualization uses quarter circles to represent around one million people. Viewers can submit their age and gender, and the visualization displays the number of people who have the same age and gender as light green quarter circles, the number of people who have the same age but a different gender as light purple quarter circles, the number of older people as dark green quarter circles, and the number of younger people as dark purple quarter circles. According to the visualization, the median age for the world’s population is around 30 years old.