In this task, you're given passages that contain mentions of a time duration related quesry and we are supposed to write answer to a question that involves event “frequency", which refers to how often an event is likely to be repeated. For example, "taking showers" typically occurs ~5 times a week, "going to saturday market" usually happens every few weeks/months, etc. 
 Note that a lot of the questions could have more than one correct answers. We only need a single most-likely answer. Please try to keep your "answer" as simple as possible. Concise and simple "answer" is preferred over those complex and verbose ones.  
Q: Sentence: The City Parliament (de: Stadtrat, fr: Conseil de ville) holds legislative power. It is made up of 80 members, with elections held every four years. The City Parliament decrees regulations and by-laws that are executed by the City Council and the administration. The delegates are selected by means of a system of proportional representation. 
Question: How often are elections held for the City Parliament?
A: 
every four years.