Population Profile

http://www.census.gov/2010census/

A population profile breaks down a country's population with age intervals, male and female distinctions, and shows the amount of people within each interval. Population trends can typically be seen when a population profile is used to show either an unchanging population, an exploding young population or an aging population. On a population profile an unchanging population looks like a rectangle, an exploding young population looks like a pyramid and an aging population looks like an upside down pyramid. The image shown above is an example of the District of Columbia having had an exploding young population twenty years ago where now it is slowly becoming an  upside down pyramid.