I guess if you count all the world the number should be between 5-6 millions overall, There are plenty of users in china, india and southern asia plus a good portion in US and canada, There aren't any accurate surveys right now but I guess it would be around that range overall.
Don't forget people in European countries there are a lot of people who are already using bitcoins there and in my opinion they are the ones who are much involved with the transaction in deep web. But the ratio of you have given that is also my estimation on many people are there already who are using bitcoin all over the world.