Think about it logically. Would it be likely to have sex with more people than you date? This would likely happen only if you engage in random sex with strangers.
So, would you expect to have sex with every friend? Seems unlikely. It’s a pretty intimate thing to do.
Would you have sex with everyone you date? Again, it seems like sex is more intimate than dataing. Unless things have changed a lot since I was a youth, getting to home base is pretty tough. You can date a lot of girls, and have sex with only a few of them. It seems like perhaps this could have changed if people don’t think much of sex any more. But I don’t think that is likely.
So most young people probably still think sex is special, and it is something people shouldn’t do unless they are serioius about each other. If that’s the case, then most people will date more than they have sex with. On the other hand, if you are incredibly sexy and don’t care who you fuck, then I suppose everyone will ask you for sex and you might just put out for all of them. Seems unlikely, though.