You are right. But the thought of it is scary, you don't know if you will get it or how severe it will be. Your stats seem correct, but the cold sore is a different kind of Herpes. Most people have gotten this from their parents or other relatives as a child, so actually it is probably closer to 80%.
There are two types of Herpes, and I think the genital herpes are different then the ones you get on your mouth that show up as cold sores.
As for syphilis... mmmmmm Well, just another reason to cover up then. Don't want to get deported!