Specific volume is inversely proportional to density. Elections use the D'Hondt method of proportional representation. It uses the principle of proportional control. This translates into a pulse from the photomultiplier of voltage proportional to the photon energy. The delegates are selected by means of a system of proportional representation. The seats are allocated by proportional representation. All elections in member states use some form of proportional representation. Numbers are placed on sliding scales at distances proportional to the differences between their logarithms. The assembly consists of 25 members elected from five districts using proportional representation. Many variations on seat allocation within party-list proportional representation exist. This has resulted in more proportional representation for voters. Italy has a parliamentary government based on a mixed proportional and majoritarian voting system. The Regional Council has 102 members who are elected under a system of proportional representation. There are also 32 senators elected by proportional representation. Delegates are elected for a four-year term on the basis of proportional representation.