The notion of a large district is defined as a grouping of several adjoining statistical blocks within the same municipality. When the municipality is divided into several cantons, the boundaries of the districts may not correspond to the boundaries of the cantons. The size of districts is highly variable. It must meet certain population norms. For example, a municipality of 20,000 inhabitants will generally not be divided into more than two or three districts; likewise only a few municipalities of less than 10,000 inhabitants are divided into districts.