The type of data collected by the US Census has varied over its history, 1790 to present. The census' primary purpose is the allocation of representatives to each state for US House of Representatives and not a complete socio-economic survey of the populace. The type of data available from the census can vary and even the questions asked by the census taker or census questionaire varies with each decennial census. The 2000 Census was the last decennial census in which detailed data was gathered from a sample of the population using the long-form questionnaire. Starting in 2001, detailed sample data is being gathered as part of the American Community Survey.