In population demographics, the dependency ratio is the number of the people who depend on the active class to take care of them.
The active class consist of roughly people aged between 16 - 65 years.
The dependent class is from 0 - 15 and 66 and above. The former are too young to earn a living, whilst the later are old and retired.
Both groups are dependent on the active population. A population that has a high proportion of these people (0- 14 years) and ( 66 and above) has a high dependence ratio.
