The Saphir 1968–2023 database contains information extracted from the 1968, 1975, 1982, 1990, 1999, 2007, 2012, 2017 and 2023 censuses. The reference periods are those of each of these censuses. The reference date for the harmonised geographical classification is that of the 2023 census geographical classification, as at 1 January 2025.