Degressive or progressive proportionality is an approach to the allocation (between parties, regions, states, or other subdivisions) of seats in a legislature or other decision-making body.
Each German state has three to six seats in the Bundesrat of Germany depending on its population.
Treaty negotiations, rather than a specific formula, determine the apportionment between member states.
Any system that reserves a minimum number of seats for a sub-body is to some extent degressively proportional.
Like the US Electoral College, Spain's Congress of Deputies adds two extra seats to the otherwise proportional number allocated to each province.