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.  
One example is below.
Q: Sentence: Namibia conducts a census every ten years. After independence the first Population and Housing Census was carried out in 1991, further rounds followed in 2001 and 2011. The data collection method is to count every person resident in Namibia on the census reference night, wherever they happen to be. This is called the de facto method. For enumeration purposes the country is demarcated into 4,042 enumeration areas. These areas do not overlap with constituency boundaries to get reliable data for election purposes as well. 
Question: How often does Namibia conduct a census?
A: every ten years
Rationale: Census is generally conducted every ten years in most countries like Namibia.
Q: Sentence: Legislative powers are exercised by a 300-member elective unicameral Parliament. Statutes passed by the Parliament are promulgated by the President of the Republic. Parliamentary elections are held every four years, but the President of the Republic is obliged to dissolve the Parliament earlier on the proposal of the Cabinet, in view of dealing with a national issue of exceptional importance. The President is also obliged to dissolve the Parliament earlier, if the opposition manages to pass a motion of no confidence. 
Question: How often are elections help for parliament?
A:
every four years