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: The government of the Marshall Islands operates under a mixed parliamentary-presidential system as set forth in its Constitution. Elections are held every four years in universal suffrage (for all citizens above 18), with each of the twenty-four constituencies (see below) electing one or more representatives (senators) to the lower house of RMI's unicameral legislature, the Nitijela. (Majuro, the capital atoll, elects five senators.) The President, who is head of state as well as head of government, is elected by the 33 senators of the Nitijela. Four of the five Marshallese presidents who have been elected since the Constitution was adopted in 1979 have been traditional paramount chiefs. 
Question: How often are elections held in the Marshall Islands?

SOLUTION: every four years

PROBLEM: Sentence: With the new stadium, Barcelona participated in the inaugural version of the Pyrenees Cup, which, at the time, consisted of the best teams of Languedoc, Midi and Aquitaine (Southern France), the Basque Country and Catalonia; all were former members of the Marca Hispanica region. The contest was the most prestigious in that era. From the inaugural year in 1910 to 1913, Barcelona won the competition four consecutive times. Carles Comamala played an integral part of the four-time champion, managing the side along with Amechazurra and Jack Greenwell. The latter became the club's first full-time coach in 1917. The last edition was held in 1914 in the city of Barcelona, which local rivals Espanyol won. 
Question: How many times did Barcelona win the Pyrenees Cup?

SOLUTION:
four