many other top universities such as University of Texas at El Paso (70% of students), Florida International University (63%), University of Miami (27%), and MIT, UCLA and UC-Berkeley at 15% each. At Stanford University, Hispanics are the third largest ethnic group behind non-Hispanic white people and Asians, at 18% of the student population. Hispanic university enrollments While Hispanics study in colleges and universities throughout the country, some choose to attend federally-designated Hispanic-serving institutions, institutions that are accredited, degree-granting, public or private nonprofit institutions of higher education with 25 percent or more total undergraduate Hispanic full-time equivalent (FTE) student enrollment. There are over 270 institutions of higher education that have been designated as an HSI. Health Longevity As of 2016, life expectancy for Hispanic Americans is 81.8 years, which is higher than the life expectancy for non-Hispanic white Americans (78.6 years). Research on the "Hispanic paradox"—the well-established apparent mortality advantage of Hispanic Americans compared to non-Hispanic white Americans, despite the latter's more advantaged socioeconomic status—has been principally explained by "(1) health-related migration to and from the US; and (2) social and cultural protection mechanisms, such as maintenance of healthy lifestyles and behaviors adopted in the countries of origin, and availability of extensive social networks in the US." The "salmon bias" hypothesis, which suggests that the Hispanic health advantage is attributable to higher rates of return migration among less-healthy migrants, has received some support in the scholarly literature. A 2019 study, examining the comparatively better health of foreign-born American Hispanics, challenged the hypothesis that a stronger orientation toward the family (familism) contributed to this advantage. Some scholars have suggested that the Hispanic mortality advantage is likely to disappear due to the higher rates of obesity and diabetes among Hispanics relative to non-Hispanic white people, although lower rates of smoking (and thus smoking-attributable mortality) among Hispanics may counteract this to some extent. Healthcare As of 2017, about 19% of Hispanic Americans lack health insurance coverage, which is the highest of all ethnic groups except for Indigenous Americans and Alaska Natives. In terms of extending health coverage, Hispanics benefited the most among U.S. ethnic groups from the Affordable Care Act (ACA); among non-elderly Hispanics, the uninsured rate declined from 26.7% in 2013 to 14.2% in 2017. Among the population of non-elderly uninsured Hispanic population in 2017, about 53% were non-citizens, about 39% were U.S.-born citizens, and about 9% were naturalized citizens. (The ACA does