The percentage of persons living by themselves is increasing. From 1970 to 1999, the percentage of adults who lived alone increased from 8 percent to 13 percent. Among individuals 18 to 24, the increase was fairly modest, from 2 percent to 5 percent. However, the percentage of individuals living alone increased from 3 percent to 10 percent among 25- to 34-year-olds and from 4 percent to 9 percent among 35- to 44-year-olds. These age groups define the life stages in which most people get married; yet over the past three decades there has been a dramatic increase in the percentage of 25- to 44-year-olds living alone.

Older Americans (persons age 65 and over) are the most likely to live alone. In 1999, about 30 percent of the population age 65 and over lived alone, a drop of one percentage point from the previous year.