Mexican Latinos make up more than two thirds of all Latinos in the United States, according to a new Pew Hispanic report.

Of the 51.9 million Latinos living in the United States in 2011, more than 33.5 million trace their family back to Mexico.

The report looked at demographic data collected from the 2011 American Community Survey. The report also examined U.S. citizenship, education levels and median income among U.S. Hispanics.

Puerto Ricans make up the second largest group, accounting for 9.5 percent or about 5 million people.

Salvadoran, Cuban and Dominican come in next with 1.9 million, 1.8 million and 1.5 million, respectively - although Salvadoran and Cuban numbers have been statistically equal and alternating yearly.

Mexican Latinos have always represented the largest segment of the U.S. Latino population.

"One of the things we've done for the first time is shown the long view of the share of Mexican Americans," Mark Lopez, associate director for the Pew Hispanic Center, told ABC News. "Since 1860, the community has diversified. In 1860, they were 81 percent, but today's numbers reflects the diversification of immigration in the U.S. … There are Hispanics from every part of Latin America and Spain in the U.S."

The report also found Mexican-Americans to be of the lowest average age (25), while Cuban Americans were the oldest, at 40.

When looking solely at foreign born Latinos in the United States, as of the 2011 data, Venezuelans and Peruvians accounted for the majority at 69 percent and 68 percent, respectively. Those two groups ranked 13th and 11th when looking at the total Latino population.

"South Americans are some of the more recent arrivals to the U.S., and the people who are coming from South America are more likely to have college degrees, more likely to be in high-paying occupations, and their family income numbers are higher," Lopez said.

Argentineans had the highest average household income in 2011, at $55,000 and Hondurans the lowest at $31,000 also giving Hondurans the highest poverty rate among U.S. Hispanics, at 33 percent. Mexicans averaged $38,000, with a poverty rate of 28 percent.

The poverty rate for Hispanics is higher than it is for the general U.S. population. According to the 2011 census, the nation's median income was $50,054 and poverty rate was 15 percent.

"Part of that is the level of education," Lopez said. "On the whole, the Hispanic community is less likely to hold a college degree than the general U.S. population. … There is still a substantial difference in educational attainment."

But Lopez said many Mexican-Americans have not "quite entered adulthood" yet, and recent years have seen a surge in the number going to college.

"Hispanics are now the largest minority group on college campuses," Lopez said. "Looking forward, its likely we are going to see the number with a college degree rise, but that is still going to be a decade or more down the road because we are just starting to see this increase among Hispanics in college enrollments."

Just over 50 percent of Venezuelans, the report found, have a college degree, while Guatemalans and Salvadorans were the least likely (7 percent).

Together, United States Latinos trace their heritage to more than 20 Spanish-speaking nations worldwide, but 14 countries represented the majority of U.S. Latinos.

As of the 2013 census, the Hispanic population is the nation's largest and fastest growing immigrant group. It stood at 53 million in 2012, making up 17 percent of the U.S. population.