this will vary from country to country. Developed countries are more aware of this so 50–60% people know about it.
In China for example this is a burning topic recently so 25–30 % are aware of Bitcoin and crypto-currency but countries like india where it's in embryo stage it is around 5–7%.

but today there are at least 15 million people using crypto. so that would be about 0.2% of world population.