Anyone have an idea of how many people know about Lucid Drea

In my house my son-in-law seems to know what it is by nature. I have a brother that had a girlfriend who was into dreams, my sister-in-law knew a guy that talked about dreams. I ask every doctor I talk to and only about 2 out of 7 know what it is. It seems the more technical doctors are informed such as specialist. Higher education I guess. And I think it’s when they are paying attention in psychology classes they pick up on it. Is there a way to get an idea of how small or large of a percentage we are?

According to How Stuff Works, they estimate only 100,000 in the USA have the ability to induce a lucid dream, but I don't know how many people know about it in general. I calculated the percentage for those who can LD, and it's .03703% of people in the USA, but I have no idea what the world's percentage is.

I had heard that five per cent of the population has had (and remembered having) at least a low-level lucid dream at some time or another, and that a fraction of a per cent were able to induce them regularly. I would very optimistically guess that one in twenty-five people knows what lucid dreams are. Most of these are philosophers, psychologists, mental doctors, or English Teachers. Seriously.