I think it depends on where you are. I live in the middle east and my Cons has informed me that a lot of the local ladies here suffer with PCOS now they all have balck hair being arabian.
I always liked to be different and I am blonde and so is my mum and we both have PCOS (cant vote for mum too!!)
it all goes down to average to I mean the uk population over 50% is brown with the remaining being divided upon the other varieties.. so it would make sense that the majority would have brown hair i think red is only about 8%
I am waffeling sorry but do you see what I am trying to get at