Birth Rate (or Crude Birth Rate) refers to the ratio of the number of births to the average population (or mid-period population) during a certain period of time (usually a year). Birth rate in the chapter refers to annual birth rate. The following formula is used: Birth Rate = Number of births / annual average population * 1000. Number of births in the formula refers to live births, i.e. when a baby has breathed or showed any vital phenomena regardless of the length of pregnancy. Annual average population is the average of the number of population at the beginning of the year and that at the end of the year. Sometimes it is substituted by the mid-year population.

 

Death Rate (or Crude Death Rate) refers to the ratio of the number of deaths to the average population (or mid-period population) during a certain period of time (usually a year). Death rate in the chapter refers to annual death rate. The following formula is used: Death Rate = Number of deaths / annual average population * 1000.

 

Natural Growth Rate of Population refers to the ratio of natural increase in population (number of births minus number of deaths) in a certain period of time (usually a year) to the average population (or mid-period population) of the same period. The following formula is applied: The natural population growth rate = ( Number of births – Number of deaths) /annual average population * 1000 = birth rate – death rate.

 

Data from National Bureau of Statistics of China