Why does the Government take a Census?
Census information essentially provides the Government and local authorities with a basis on which they can try to predict the future.
Planning and demands for services, both nationally and locally, are the largest benefit of bringing together the vast data of a Census.
The population statistics - along with age demographics - at national level, gives a blueprint to work from on the healthcare, education and employment needs of the country.
However, Central Statistics Office (CSO) officials believe that its most important aspect is the detailed population statistics that are provided at a local level.
These help to identify likely demand for schools and healthcare facilities.
They even go as far as to indicate the best possible location for a new shop.
Outside of infrastructure and the needs for essential services, the data correlated also has a snowball effect on the number of representatives, both local and national, required for a particular area. The Irish Constitution says that the number of TDs at Leinster House is dictated by the population recorded in the Census, and then works out the number of people for every TD.
It also accurately records migration.
"By comparing the results of successive censuses, and taking account of the number of births and deaths over the same period, we get an accurate measure of net migration," a CSO official said.
A Census has been held in Ireland on average every five years since 1951. The first was recorded in 1821.