• Data reference period
• Geographic localization (Portugal)
• Sex

• REFERENCE PERIOD:  The length of time for which data are collected, e.g. a specific day, month or year.
• 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.
• WORKING AGE POPULATION RENEWAL RATIO:  The ratio between the population that is potentially entering and that which is leaving the labour market, normally defined as the quotient between the number of people aged between 20 and 29 years and the number of people aged between 55 and 64.
• ENTERPRISE:  Legal entity (natural or legal person) that is an organisational unit producing goods or services, which benefits from a certain degree of autonomy in decision-making, especially for the allocation of its current resources. An enterprise carries out one or more activities at one or more locations.

(Resident population aged between 20 and 29 years old/ Resident population aged between 55 and 64 years old)*100

Where: Resident population represents the population at the censitary moment.