of predominantly Native American descent with varying levels of European admixture, with the rest are of predominantly European (most especially Iberian) descent with varying levels of Native American admixture. Official sources report that the racial makeup of Hispanic subgroups from the countries Uruguay, Cuba, and Chile have the highest proportion, for their respective countries, of Hispanics in the US self-identifying as white – though in raw numbers the highest number of white Hispanics in the United States are Mexican Americans. As a result of their racial diversity, Hispanics form an ethnicity sharing a language (Spanish) and cultural heritage, rather than a race. The phenomenon of biracial people who are predominantly of European descent identifying as white is not limited to Hispanics or Spanish speakers but is also common among English speakers as well: researchers found that most white Americans with less than 28 percent African-American ancestry say they are white; above that threshold, people tended to describe themselves as African-American. Age As of 2014, one third, or 17.9 million, of the Hispanic population was younger than 18 and a quarter, 14.6 million, were Millennials. This makes them more than half of the Hispanic population within the United States. Education Hispanic K–12 education With the increasing Hispanic population in the United States, Hispanics have had a considerable impact on the K–12 system. In 2011–12, Hispanics comprised 24% of all enrollments in the United States, including 52% and 51% of enrollment in California and Texas, respectively. Further research shows the Hispanic population will continue to grow in the United States, implicating that more Hispanics will populate U.S. schools. The state of Hispanic education shows some promise. First, Hispanic students attending pre-K or kindergarten were more likely to attend full-day programs. Second, Hispanics in elementary education were the second largest group represented in gifted and talented programs. Third, Hispanics' average NAEP math and reading scores have consistently increased over the last 10 years. Finally, Hispanics were more likely than other groups, including white people, to go to college. However, their academic achievement in early childhood, elementary, and secondary education lag behind other groups. For instance, their average math and reading NAEP scores were lower than every other group, except African Americans, and have the highest dropout rate of any group, 13% despite decreasing from 24%. To explain these disparities, some scholars have suggested there is a Hispanic "Education Crisis" due to failed school