An age-sex structure is a chart that shows the number of people in a given population, broken down by sex and by different age groups. The chart shown here is a dynamic model of the population of Russia from the year 1990 to the year 2050.

Take notice of several things while viewing this chart:

1. First of all, notice the decreasing size of the bars of the graph throughout the entire chart. This represents the projected shrinking of Russia's population.
   
   
2. Next, notice that the shape of the distribution changes from a somewhat pyramidal shape to an inverted pyramid. This demonstrates the fact that Russia's population is aging significantly. In the beginning of the sequence, the "traditional pyramid" shape is shown because Russia has more young people than old people. However, as time progresses, we see a shift in population trends, such that the 60+ portion of Russia's population becomes greater than the younger portion, and the chart takes on an "inverted pyramidal" shape.