The Belgian law of 28 June 1932, on the use of languages for administrative matters based the language status of every Belgian municipality on the decennial census that included, since 1846, several language questions about the knowledge as well as the day-to-day practice. The criterion to belong to the Flemish- or Walloon-language area was a threshold of 50%; whereas with a threshold of 30% the municipal authorities had to offer services in the minority language as well. A municipality could ask the government to change its linguistic status by a royal decree only after a census showed a passage over the 30% or 50% threshold.