I thought the rule was that the minimum age was = 1/2 x (your age) + 6.
Only a year different from what i was told. Need to look at the low end, though, to stay out of jail. When you hit my age, adding either 6 or 7 is an insignificant difference.
I was taught it’s the desirable age, not minimum. See Anna Nicole Smith and her wealthy husband for an example.