The Kennedy assassination is one of America's where-were-you-when moments. But with its 50th anniversary on Friday, there are fewer and fewer Americans who can say where they were. In fact, Census data suggests that only about a third of America's current population was alive on that day in 1963 — and less than 30 percent might actually remember.

To figure this out, we pulled the Census Bureau's projected population tables that extrapolate likely population from the 2010 Census out to 2060. For the year 2013, it offers an estimated count of every American of every age: there are just over 4 million 1-year-olds, about 590,000 people who are 89. What this means is that we can say, with some certainty, how many Americans are now 50 or older — in other words, how many people were alive for the assassination.

Namely:

But not all of those people remember the assassination. People born on November 20, 1963, certainly don't. Assessments of the age at which people first form memories vary, but we decided to use 3 years of age as the benchmark. If you were born on November 20, 1960, there's an outside chance you'll remember at least the tumult that resulted from the shooting.

That Census data isn't only good for determining how many Americans alive today remember the assassination. If we extrapolate outward, all the way to the 95th anniversary in 2058, we can see how many of those alive at the killing will themselves have survived. By then, under a million people — 0.74 percent of the country — will be older than the assassination. For those who might actually remember it, people who are slightly older? 343,000. Which, honestly, is a higher number than might have been expected.