If 60-90% of Americans have oral herpes, how come more people don't have genital herpes?

If the percentage is so high and you can pass herpes without even showing signs, then why isn't it passed from oral sex? I doubt that all people realize that they have cold sores especially in the early stages...I just figured that it would be more prevalent since HSV-1 and 2 can be present in either oral or genital regions