Living arrangements in the U.S. are changing. One generation ago (1990), married-couples were 55% of all households. In 2018 it had declined to only 48%. If we go back two generations to 1960, married-couples back then were almost three-quarters of all households (74.2%), one-half more than today.
The most dramatic drop has been with under age 25, where the current rate is less than half of what it was in 1990. The second greatest decline is with middle Millennials, age 25-34, where there has been an almost one-quarter decline in married households.