The availability of reliable, up-to-date and continuous vital statistics depends on the level of development of civil registration systems. Vital statistics is not always available for all countries in the world. For some, basic birth and death statistics can only be obtained from population censuses and sample surveys, which tend to suffer from random errors, recalling errors, and lack of continuity.

The chart below shows the percent of countries that have provided total number of births and /or deaths for at least one year in the period 2003 - 2007, by region. The chart also indicates the data source that was used by countries, whether it was complete civil registration, incomplete or questionable civil registration, or population censuses and sample surveys.