TASK DEFINITION: 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.  
PROBLEM: Sentence: Chopin's music remains very popular and is regularly performed, recorded and broadcast worldwide. The world's oldest monographic music competition, the International Chopin Piano Competition, founded in 1927, is held every five years in Warsaw. The Fryderyk Chopin Institute of Poland lists on its website over eighty societies world-wide devoted to the composer and his music. The Institute site also lists nearly 1,500 performances of Chopin works on YouTube as of January 2014. 
Question: How often is the International Chopin Piano Competition held?

SOLUTION: every five years

PROBLEM: Sentence: Also founded in 1935 and based in Detroit the Michigan Chronicle is one of the oldest and most respected African-American weekly newspapers in America. Covering politics, entertainment, sports and community events. The Detroit television market is the 11th largest in the United States; according to estimates that do not include audiences located in large areas of Ontario, Canada (Windsor and its surrounding area on broadcast and cable TV, as well as several other cable markets in Ontario, such as the city of Ottawa) which receive and watch Detroit television stations. 
Question: How often does the Michigan Chronicle publish?

SOLUTION: weekly

PROBLEM: Sentence: The Gregorian calendar is a solar calendar. A regular Gregorian year consists of 365 days, but as in the Julian calendar, in a leap year, a leap day is added to February. In the Julian calendar a leap year occurs every 4 years, but the Gregorian calendar omits 3 leap days every 400 years. In the Julian calendar, this leap day was inserted by doubling 24 February, and the Gregorian reform did not change the date of the leap day. In the modern period, it has become customary to number the days from the beginning of the month, and February 29th is often considered as the leap day. Some churches, notably the Roman Catholic Church, delay February festivals after the 23rd by one day in leap years. 
Question: How often is a leap day added to the Julian calendar year?

SOLUTION:
every 4 years