I saw this meme on Facebook. I have not checked its accuracy, but it seems likely:
70% of 18 - 29 year olds did not vote
60% of 30 - 44 year olds did not vote
Only 38% of 45 - 64 year olds did not vote, and
Just 15% of 65+ citizens did not vote.
To which I would add, people who vote live longer.
This is not snark; people who vote tend to be involved in many aspects of their community, and belong to organizations that serve causes larger than themselves.
People who do those things tend to live longer.
So the older the cohort, the more it tends to boil down to the involved people, including voters.