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: These limitations have caused problems. For example, before 2005, DST in Israel varied each year and was skipped some years. Windows 95 used rules correct for 1995 only, causing problems in later years. In Windows 98, Microsoft marked Israel as not having DST, forcing Israeli users to shift their computer clocks manually twice a year. The 2005 Israeli Daylight Saving Law established predictable rules using the Jewish calendar but Windows zone files could not represent the rules' dates in a year-independent way. Partial workarounds, which mishandled older time stamps, included manually switching zone files every year and a Microsoft tool that switches zones automatically. In 2013, Israel standardized its daylight saving time according to the Gregorian calendar. 
Question: How often would Israeli users running Windows 98 need to manually adjust the time on their machines to stay current?

SOLUTION: twice a year

PROBLEM: Sentence: More recently, films such as Das Boot (1981), The Never Ending Story (1984) Run Lola Run (1998), Das Experiment (2001), Good Bye Lenin! (2003), Gegen die Wand (Head-on) (2004) and Der Untergang (Downfall) (2004) have enjoyed international success. In 2002 the Academy Award for Best Foreign Language Film went to Caroline Link's Nowhere in Africa, in 2007 to Florian Henckel von Donnersmarck's The Lives of Others. The Berlin International Film Festival, held yearly since 1951, is one of the world's foremost film and cinema festivals. 
Question: How often is the Berlin International Film Festival held?

SOLUTION: yearly

PROBLEM: Sentence: Some of the cleaner energy facilities in Boston include the Allston green district, with three ecologically compatible housing facilities. Boston is also breaking ground on multiple green affordable housing facilities to help reduce the carbon footprint of the city while simultaneously making these initiatives financially available to a greater population. Boston's climate plan is updated every three years and was most recently modified in 2013. This legislature includes the Building Energy Reporting and Disclosure Ordinance, which requires the city's larger buildings to disclose their yearly energy and water use statistics and partake in an energy assessment every five years. These statistics are made public by the city, thereby increasing incentives for buildings to be more environmentally conscious. 
Question: How often is Boston's climate plan updated?

SOLUTION:
every three years