• Data reference period
• Place of residence (NUTS - 2013)

• RESIDENT POPULATION:  Set of persons who, regardless of being present or absent in a given housing unit at the moment of observation, have lived in the place of their usual residence for a continuous period of 12 months prior to the moment of observation, or have arrived to the place of their usual residence during the period of 12 months prior to the moment of observation, with the purpose of living there for a year, at least.
• AGE DEPENDENCY RATIO OF THE YOUNG (YOUNG-AGE DEPENDENCY RATIO):  The ratio of the number of young persons of an age when they are generally economically inactive (either under 15 or under 20 depending on the context) to the number of persons of working age (from 15 to 64 or from 20 to 59 depending on the context).
• REFERENCE PERIOD:  Period to which the information refers and which may be a specific day or a time interval (month, fiscal year, calendar year, among others).

YDR=[P(0, 14)/ P(15,64)]*10^n

P(0, 14)=Resident population aged between 0 and 14 years old.
P(15, 64)=Resident population aged between 15 and 64 years old.
n=2.