Crude death rate (CDR)
"There are three numbers that capture fertility: TFR, CBR, the fertility distribution. There are three numbers that caputure mortality: LIFEXP, CDR, mortality distribution. They will not be completely compatible. The distributions must be used to handle cohort dynamics. But they may not be available for all countries (e.g. Taiwan, Palestine), whereas the others are. For many years we used CBR and CDR to adjust the distributions and then calculated TFR and LIFEXP from them. Over time, TFR and LIFEXP have become the key variables that dynamically drive the population model, and good data are now available. We have therefore switched over to them as the bases for initial conditions of the model, calculating CBR and CDR from them, giving us also POPR."