By 2020 at list 40 to 50 percent of world population should own bitcoin and even use it. Many young men and girl has access to internet and bitcion is making great Wave all over the world and people becomes knowledgeable about bitcoin and others cryptocurrency.
I believe that to be about 10%-20% of people in this world.
Well, do you know that lots of people in the world does not make use of the Internet ! So, we still have a long way to go. But, we shouldn't be predicting the future, we should wait and see what happens.