For Vietnam, population for subnational areas. Sex and residence breakdowns are national only, and start at 1990. Subnational detail starts at 1995.
The survey has a reference date of April 1st.
The General Statistical Office (GSO) along with the National Committee for Population and Family Planning (NCPFP) annually conduct a survey of population change and family planning.
The survey is of 200,000 households, approximately 3,000 in each province.
The survey consists of two parts, the first on population (number in household, age, sex, marital status, births, deaths, and migration in the past year) and the second on family planning of married women 15-49 years (number and dates of birth of children, number still living, educational levels, family planning methods used, and abortion).
Data is revised when new data becomes available.