The use of administrative records in Finnish population censuses began in 1970 and has been increasing ever since. The Population and Housing Census of 1990 was the first totally register-based, without using a single questionnaire. Since 1987 Statistics Finland has produced an annual data base for the entire population. Information is produced for the nation but can also be produced for smaller areas such as provinces and municipalities and parts of municipalities. Census data are used to compile longitudinal data files in which each resident of the country is linked with his or her data in different Censuses. Another data file combines the annual data from 1987 to 1997. This makes it possible to follow the life course of each person, and all the changes that have occurred. Changes in the Labour Force have been compiled by monitoring the flows of population and labour force from one status to another in different years.