I wonder if there's some information about the ratio of high vs. low CRT people. Are most people low/medium/high? Is there some kind of a bell-curve for distrib

I wonder if there's some information about the ratio of high vs. low CRT people. Are most people low/medium/high? Is there some kind of a bell-curve for distribution in the general population? between genders or ethnic groups? This can certainly help deciding what's the best marketing strategy for products or services.