> numbers alone will make discrimination against people with tattoos difficult

We must live in different worlds, because I can count the number of people I know with tattoos on one hand. "discrimination" happens regardless, since it's a surprisingly good indicator of social status. Number won't change anything, unless it becomes fashionable in the correct strata.

Frankly, I find them a debasement. The human body is a beautiful thing, why would you want to draw some crass scribbles on it?