• Data reference period
• Geographic localization (Portugal)
• Highest completed level of education

• 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).
• LOCAL UNIT:  An enterprise or part thereof (e.g. a workshop, factory, warehouse, office, mine or depot) situated in a geographically identified place. At or from this place economic activity is carried out for which ' save for certain exceptions ' one or more persons work (even if only part-time) for one and the same enterprise.
• EDUCATIONAL QUALIFICATIONS:  The degrees, diplomas, certificates, professional titles and so forth that an individual has acquired by study.

Estimated of total average annual gross earnings of full-time employees (remunerated for the entire year)/ Estimated number of full-time employees (remunerated for the entire year)