1990 POPULATION CENSUS Detailed data based on a 2 per cent representative sample (1992)
V. EXPLANATION OF CONCEPTS
Both to the permanent and the resident populations belong alsó those persons who have no permanent dwelling but whose temporary residence at the census moment was in the respective area (e.g. a part of the inhabitants of charitable institutions, temporary accommodations, alms-houses). 2 Population density means the number of persons per 1 km of the respective area. POPULATION INCREASE The actual increase and decrease, respectively, mean the difference between the population sizes enumerated in an area at two consecutive population censuses; in the 1B70-1960 period this value was that of the population present at the census moment and in the 1970-1990 that of the resident population. The population censuses of 1870-1890 referred only to the civil population, and, consequently, the data of the actual increase of the 1891-1900 period differs from the difference between the 1890 and 1900 population sizes. The natural increase and decrease, respectively, means the balance of live-births and deaths in the population of a given area. Live-birth is the coming into the world of the foetus, regardless to how long it was in the mother's uterus and how long it lived, provided the foetus gives somé sign of life (e.g. breathing, heart function, decisive motion of the volitional muscles, pulsation of the umbilical cord). Death is the final cessation of all signs of life at any time after live birth (the cessation of the functions of life after delivery without the capability of revival). Net migration is the difference between the actual and, respectively, natural increase and decrease. Average yearly increase and decrease are counted on the basis of the hypothesis that between two population censuses the population increases or decreases according to a geometrical progression, i.e. the rate of change /r/ is constant. The calculation formula is P n = po <l +r> n from which r = \ po -1 P 0 = the size of the population at the date of the population census taken at the beginning of the period P n = the size of the population at the date of the population census taken at the end of the period n = number of years (fractions of years) elapsed between the two population censuses AGE-GROUPS The data of the age structure of the population were detailed by age-groups on the basis of the age completed till the census moment of the population censuses. The table presenting the distribution by age as well as by marital status, contain the data by five-year and major age-groups. In the data processing of the 1990 population census, the individual age-groups cover the following birth cohorts: 251
