The combination of husband, wife, and children that 99.8 percent of people in the United States believe constitutes a family is not representative of 99.8 percent of U.S. families. According to 2010 census data, only 66 percent of children under seventeen years old live in a household with two married parents. This is a decrease from 77 percent in 1980 (U.S. Census 2011). This two-parent family structure is known as a nuclear family, referring to married parents and children as the nucleus, or core, of the group. Recent years have seen a rise in variations of the nuclear family with the parents not being married. Three percent of children live with two cohabiting parents (U.S. Census 2011).