Population profile

 A population profile measures variances of a given population trend measured over time.  In this particular map the trend is age distribution over three decades.  This information could be used to compare the past trends to predict the future population numbers in decades to come.

http://www.co.nezperce.id.us/Departments/PlanningandBuilding/ComprehensivePlan/ComprehensivePlanHomePage/Population.aspx