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Despite greater access to birth control, more accepting attitudes toward sexual behavior in general, and technology that makes it easier for people to hook up, Americans are having less . New research shows a steady decline in sexual activity over the past few decades. On average, people are having sex nine times less per year than in the late 1990s.

So what gives?

A few interesting findings stand out. For starters, Millennials are less sexually active than previous generations. Although it can be easy to view Millennials as having more sexual freedom than prior generations, there’s a catch: Millennials are less likely to be partnered or married than prior generations. While some may think that a single lifestyle must be filled with sexual adventures, the data paint a different picture. It’s much easier to have sex when you’re partnered. When you’re single, it takes more time and effort to find someone for an intimate encounter than for those with a partner present. Most likely due to convenience, people in relationships have twice the amount of sex as their single counterparts.

But it's not all good news for people with partners. While those in a steady relationship do have a sexual advantage over their unpartnered peers, this advantage has been decreasing over time. Couples, too, are now having sex less often than in the past. And there’s no clear culprit — neither working longer hours nor easier access to appears to explain why sexual is on the decline. The research shows that couples who put in longer hours at work, and those who watched porn more often, have more sex than couples who didn’t.

Unfortunately, the researchers weren’t able to pinpoint exactly why couples are having less sex than in the past. It’s possible that the dramatic increase in leisure-time activities, such as video streaming and social media, are crowding out the time couples used to spend in the bedroom. Could it be that Netflix and Facebook are taking away time that was once spent on sexual intimacy? The trend of having children later in life may also play a role. Hitting middle age, combined with young children in the house, probably doesn’t set the scene for a night of romance.

Whatever the reasons, the decline in sex is not a trivial concern. Research consistently shows that people who have more frequent sex are happier and more satisfied with life than those who have sex less often.

The decline in sexual activity has been steady. Will it continue to drop, and what, if anything, can be done about it? One legislator in Sweden is taking a rather novel approach. He recently proposed giving people an hour-long paid break once a week for the sole purpose of having sex with their partners. Who could’ve imagined that we might ever have needed to find creative ways to encourage people to have more sex?