Detailed Instructions: In this task, we ask you to write an 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 answer. 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.
See one example below:
Problem: Sentence: Jack played basketball after school, after which he was very tired. 
Question: How often does Jack play basketball?
Solution: twice a week.
Explanation: "Playing basketball" normally occurs few times a week.

Problem: Sentence: At current rates of use, coal will last about 300 years. 
Question: How often are the coal reserves calculated?
Solution:
once a year.