We normally look at crimes by rates, X per 100,000, so the fact that the total population is quite a bit bigger between the two periods is significant.

So is the fact that the item you're comparing today's still living, old Boomers to a by definition much younger Millennial population. There were once quite a few more Boombers, and circling back to my entire point, young Boomers of the criminal producing age.

No, I'm comparing the 75 million living Millenials to the 79 million peak population of the Boomers. But I repeat myself.

I also disagree that a ~5% difference would be likely to drive significant differences in crime rates.

Later: Yes, that Millenials are a smaller percentage of the population would complicate the comparison.