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As written, the answer to your question is around 1.5 billion to 1, if you consider the five people on the International Space Station to be "traveling through space."
I suspect you meant to write "what is the ratio of the aging rate of people on Earth to the aging rate of those traveling through space." In that case the answer for all practical purposes is 1 to 1, since the relativity effect on the ISS is extremely small. (If you want precision, it's about 0.9999999986 to 1.)
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