In this task, you're given an ambiguous question (which can be answered in more than one way). Your task is to write a question that clarifies the given question in such a way that the generated question has one unique answer.
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Question: When did the first usb flash drive appear on the retail market?

Answer: When did the first usb flash drive appear on the global retail market?


Question: When did the soviet union test its first atomic bomb?

Answer: When did the soviet union first test its first atomic bomb?


Question: What percentage of the us population has a phd?

Answer:
For people age 25-30, what percentage of the US population has a phd?