• Data reference period
• Place of residence at Census date [2021] (NUTS - 2013)
• Sex

• ILLITERATE:  Indivíduo com 10 ou mais anos que não sabe ler nem escrever, i.e., incapaz de ler e compreender uma frase escrita ou de escrever uma frase completa.
• PLACE OF USUAL RESIDENCE:  Place in which a person normally spends the daily period of rest (regardless of temporary absences for purposes of leisure, holiday, visits to friends and relatives, business, medical treatment, or others) and where the person lives or intends to live for the most part of the year, taking the last 12 months as reference.
• 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.

(Resident population with 10 and more years old ("It does not know to read or write")/ Resident population with 10 and more years old)*100