Oh, boy - we (US adults) are doing "it" less than we did during the 1990's; an average of 9 times less per year, in fact. It's not entirely clear what the cause is - more single adults, or some other cause, but it does seem to be a measurable difference over a wide range of social conditions.
SlashdotThe study is based on data from a long-standing national survey called the General Social Survey (GSS). It involves a nationally representative sample of Americans over 18 years old, surveyed most years between 1972 and 2014. The new study involved responses from 26,620 Americans. Specifically, researchers found that married people's annual whoopee frequency dropped from an average of nearly 69 in the 1995-2000 period to just below 56 in the 2010-2014 period. The unmarried saw their lovemaking drop from 54 per year to 51 in the same timeframes.