The article doesn't really mention if the numbers are related to sexual partners or number of times the deed is performed. Many years ago, I remember my friend having "encounters" with many different women usually lasting one night. While I had only a few partners, but had much higher deeds.

I've noticed "the youth" in general are kind of like my friend. Not into settling down, but rather going for the variety. However, it takes a lot to hook up, even with apps like Tinder. Hence I think people are having less sex.