most of the people around the world knows bitcoin already. it has already publish on public media like television, social media and other media platform.
I guess not all are interested and most of them don't care about it.
Yes I gues 40-60% already knew about bitcoin.But I doubt if all are involved in bitcoin or join bitcoin.Social Media and some television network where talking and reported about bitcoin.But most listen but not interested specialy the older one,in my country 1/4 of population are senior cetizens they are familiar in computers but dont know how to use it.Maybe 40-60% knew the popularity of Bitcoin but few where interested to join.In my calculation 20-40 years old are the age range of the people who join and understand bitcoin.