The number of immigrants living in the U.S. jumped from 9.7 million to 42.2 million over the last half century, almost tripling the overall percentage of immigrants now accounting for the total size of the U.S. population.

A Pew Research Hispanic study finds immigrants now compose 13.2 percent of the U.S. population, compared to just 5.4 percent back in 1960.

In addition, Hispanics are now the youngest U.S. ethnic group, with roughly one-third, or 17.9 million, of the country's Hispanic population 18 or younger. Researchers also found about one in every four, or 14.6 million, of all Hispanics are considered millennials, falling within the 18 to 33-year-old demographic.

Most Hispanics are Considered Millennials

Overall, roughly 60 percent of all Hispanics are considered millennials, compared to around 50 percent of the African American population and 46 percent of the U.S. Asian population.

Researchers also found whites to be the country's oldest racial group, with roughly just four in ten, or 39 percent, of all the group's population classifying as millennials or younger.

The median Hispanic age of 28 was also found to be much younger than that that of other groups. In addition, 44 percent of all Hispanic eligible voters were found to be millennials, a group that represents the largest single voting bloc of all Latinos.

Among Hispanic millennials, researchers found group members are much less likely to be immigrants and much more likely to speak proficient English.

Data shows about half, or 47 percent, of all Latinos are the offspring of immigrants, many of whom only recently migrated to the U.S. Thus, the average age of foreign-born Hispanics (41) is more than two decades more than that of U.S.-born Latinos (19).

With so few children migrating to the U.S. at any early age, young Latinos overwhelmingly prove to be U.S. born. In all, 94 percent of Latinos younger than 18 were born in this country and roughly two-thirds of all Hispanic millennials are American born.

Most Young Latinos Living in U.S. Overwhelmingly Speak Proficient English

In all, researchers found 88 percent of all Hispanics living in the U.S. between the ages of five to 17 speak proficient English and an overriding percentage of them are American born.