Since early times, governments have been taking official counts of the population in their country. The United States was the first nation in modern times to make the regular taking of a census part of its constitution. But in the 11th century William the Conqueror ordered a survey of all the lands in England, their value and their owners, and this is still in existence, providing a record of that early census. It is called the Doomsday Book.
Since 1801, a U.K. census has been taken every ten years, and looking at the figures since then we can see immediate changes that have taken place since then. For instance, in 1801 there were only 11,944,000 people in the U.K. Now there are over 55,500,000.
In a census, much more information is gathered than just the number of people. There are questions about whether the people are married or single, about the kind of home they live in, the amount of schooling they had, their occupation, and so on.
This additional information is very valuable and important in making decisions in many areas. For example, it can help determine how many schools and teachers are necessary. It can help guide us about what social legislation is needed for older people. It can tell us what effects population changes will have on the labor market, and many other matters.
There are also other censuses taken at different times pertaining to agriculture, manufacturers, mineral industries, business, government units, and irrigation and drainage.
