Population statistics related concepts

Population statistics: the whole process of collecting, sorting out and analyzing population phenomena and quantitative data. Population statistics is the need to adapt to social development and national management, and the development of human society, is the oldest of the history of a statistical.
Total population: also known as the total population, a certain time, a certain geographical (space), the sum of all the residents, that is, the total of the local people living alone. The total population is the most basic indicator of population statistics, which is based on the calculation of population structure, population quality, population increase or decrease, and population forecast.
Population changes in the number of people who have died of birth. The absolute number of population changes in the absolute number of people within a certain period of time, the number of births and deaths, known as the number of natural population increase. The relative numbers of natural population changes during a certain period of time, the number of natural population increase with the average population of the period, known as the natural population growth rate, the general use of a thousand points said.
Population migration: also known as demographic changes. Population movement in the space, from a region to another region, and the number of changes caused by the increase or decrease.
Census: in order to investigate the changes of population in China in terms of quantity, structure, distribution and living environment etc. to co-ordinate arrangements people's material and cultural life, to realize the sustainable development strategy, decision of the State Council, a national census every 10 years, has been carried out with six times, in 1953, 1964, 1982, 1990, 2000 and 2010 respectively.
Average population: the average number of people in a certain period of time. The number at each time point can only represent the size of the population at that time, and can not represent the population size of a period (e.g., season, year).
Sex ratio: the ratio of men to women in the population. Usually expressed in every 100 women population corresponding to the male population.
Sex ratio: the ratio of the number of male and female infants born to a certain period of time. The sex ratio of the baby is the basis of the sex ratio of the whole population. Because of the difference in mortality between men and women in all age groups, the sex ratio of the other age groups was different than that of the sex ratio at birth. The sex ratio of the baby was between 103-107.
Sex ratio imbalance: the world's long-term observation of the results showed that the vast majority of the country is always slightly higher than the number of baby girls, birth sex ratio is generally about 105. In the larger geographical range, the total population of the sex is in an unbalanced state, which is called the sex ratio imbalance.