The Middle Age is the average age of the inhabitants in an area. This data can be used in order to calculate IDH, the Birth rate and of Scolarisation as well as the percentage of the Active population.

To calculate the average age

Summon ages of the inhabitants of the area/Nombre of inhabitants of the same area

for example, if the area is made up of 2 inhabitants having 15 and 20 years, the average age will be 17,5 years