I wish I was good enough at math to use these tables to figure out what percentage of the population is within a particular age range in any given year. In par

I wish I was good enough at math to use these tables to figure out what percentage of the population is within a particular age range in any given year. In particular, I'm curious to see what years the population of particular generations peaked. Edit: Actually what I'm really looking to do is to correlate certain marketing demographics with generations. For example, "in what years did Generation X comprise the majority of living people in the 18-34 demographic?" (where Generation X is defined as people born 1961-1981).