This is for my own curiosity. Is there any place I can look to find how many people were born in a given year and the percent that are still alive today?
Whether this is possible depends on how records are kept in the community that you are testing.
Most countries register both births and deaths, but the two registrations are unlinked – i.e. when they register your death, they don’t create a link to the registration of your birth. Consequently it isn’t easy to identify which members of the cohort born in a given year are still alive.
There may be a few countries which do link birth and death records this way, so you’d have better luck there. But even there, the match is not complete; a birth record which does not have a linked death record may indicate someone still alive, or it may just indicate someone who has emigrated. Conversely there will be people who immigrated, whose death records cannot be linked to birth records because their birth records are in another country. So although born in (say) 1942, they won’t show up in a count of those born in 1942 who have since died.
(It is, of course, easy to estimate statistically, since the actuaries have fairly solid estimates for life expectancy for people of any given age. And then you can refine your estimates by testing them against figures for social security claimants, etc. But I don’t think that’s what you’re asking.)