Do you have a link? I'd be curious to see how it relates to actual marriage rates, ages, demographics, etc.
http://rhiever.github.io/marriage-divorce-stats/marriages_divorces.html
There's a lot of other stuff floating around, too, but that's the starting point.
Basically:
Divorce is at the lowest level it has been since the 70s, even controlling for marriage rates.
Marriage rates are also down, but the downwards trend in recent years has been in very large part attributable to very late marriages (27 is the current average age of marriage, which is among the latest points in history.)
In other words: If you treat 27 as the new (early 20s or whatever the average age was) marriage rates are pretty close to normal. A lot of older methodologies simply looked at "married past 25" to establish marriage rates, which is silly given when people are getting married now.
If you throw in cohabitation studies, which are a bit harder to do, it looks like 'marriage' rates have risen slightly, and divorce rates haven't dropped by quite as much as the data suggest: some of the couples that would have gotten divorced simply cohabit for a period of time and never bother getting married.
In terms of premarital sex:
Yeah, its up.
However, adolescent sex is down: People are waiting to have sex, and far fewer people are having sex in high school. I'm not looking that up right now, because I don't really want to sort through the results of "teenage sex." It's pretty easy to find, though, and I think that study got posted here. Sex is more common before marriage, though I'm not sure its more common per year/person, merely that there are far more years between the onset of sexual activity and marriage now. This last part is pretty hard to test, though: people were also far less honest about sex at certain points in history, though there's evidence of a reasonably consistent level of infidelity and other sexually 'deviant' behaviors. Even if the onset has moved back a couple years, marriage has moved back far more.