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: 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?
Solution is here: every ten years
Explanation: Census is generally conducted every ten years in most countries like Namibia.

Now, solve this: Sentence: FC Barcelona had a successful start in regional and national cups, competing in the Campionat de Catalunya and the Copa del Rey. In 1902, the club won its first trophy, the Copa Macaya, and participated in the first Copa del Rey, losing 1–2 to Bizcaya in the final. Hans Gamper — now known as Joan Gamper — became club president in 1908, finding the club in financial difficulty after not winning a competition since the Campionat de Catalunya in 1905. Club president on five separate occasions between 1908 and 1925, he spent 25 years in total at the helm. One of his main achievements was ensuring Barça acquire its own stadium and thus generate a stable income. 
Question: How many times between 1908 and 1925 was Gamper president?
Solution:
five