Countries that do not have a well-functioning civil registration system only have approximate ideas of the Numbers, the longevity and the health of their population.
那些没有建立完善民事登记系统的国家对其人口的数量、寿命和健康状况，往往只有一些粗略的概念。
2
Sample registration, which involves tracking a small part of the population, can also be used in the absence of full civil registration.
在缺乏全员民事登记的情况下，可以采用跟踪一小部分人口的抽样登记的办法。
3
Recent death registration data were available for 83 countries, comprising 28% of the global population.