which are entitled to more than one seat is determined using the largest remainder method. Cantons which are only entitled to send one councillor to the National Council elect the candidate who wins a majority of votes. The cantons use a unique system of proportional representation, sometimes called a "free list". Each citizen may cast as many votes as there are seats available to their constituency, and may even cast up to two votes for the same candidate. For every vote received by a candidate, that candidate's party also receives a vote. Voters also list a party vote, in which all blank candidate votes contribute towards the party's total. In elections, political parties publish lists in the cantons with their candidates. Each list contains at most the number of candidates which the canton is entitled to send to the National Council. In addition, each party can produce multiple lists to the canton (e.g. men's, women's, youth, or seniors' lists; in larger cantons they might offer lists for individual cities or districts). It is also possible for several parties to enter a single shared list. Voters may choose a pre-prepared party list without making changes or they can alter it by cumulative voting or panachage. Thus, the voter can give his vote to a specific candidate and ignore the rest of that candidate's party. Alternatively, it is possible for the voter to split his or her vote among several candidates from different parties. The seats are then apportioned using the Hagenbach-Bischoff System. This system is unique in that it allows voters to split their vote across different parties, depending on which candidate the voter prefers. Fictional voter To determine a party's strength, the notion of "fictional voter" was introduced and is defined by the Swiss Federal Statistical Institute as: number of votes obtained by party A * (number of valid ballots / number of valid votes). Individual voters can choose to make fewer than the permissible number of votes. The number of valid votes / number of valid ballots closely matches the number of deputies a canton needs to elect. More exactly, this number represents the average number of valid votes per voter. The formula can then be summed up by: number of votes obtained by party A / average of valid votes per voters. The result is the number of fictional voters for a given party in a given canton.