Updated

For the first time since Puerto Rico became a U.S. territory, its population has experienced a sustained decline, according to a new study.

The study, by the Pew Research Center, found that between 2010 and 2013, more people left the island for mainland U.S. than people who left in the 1980s or 1990s.

At the same time, the number of Puerto Ricans on the U.S. mainland reached a record – 4.9 million in 2012. The population on the mainland has surpassed that of the island, at 3.5 million, since 2006, the study said.

The impetus was “job-related reasons above all others,” the authors wrote. Puerto Rico has been struggling with a nearly decade-long economic slump.

“The island’s economic crisis may be driving thousands of Puerto Ricans to seek opportunities on the mainland, or to return there,” the report said.

Some 42 percent gave looking for better job opportunities as reasons for leaving the island, compared with 38 percent who cited joining family. Mainland-born Puerto Ricans, who are younger and are more likely to have attended college than their island born counterparts, accounted for much – a third – of the population loss.

The island faces about $73 billion in public debt after having sold a record $3.5 billion in general obligation bonds in March despite having its credit rating downgraded to junk status.

In a statement to Fox News Latino in response to the Pew findings, Puerto Rico Governor Alejandro García Padilla maintained that the island has made strides.

“Since entering office, I have worked tirelessly to reform key institutions, attract new business investment and improve the lives of families – in other words, making the hard choices and necessary reforms that previous administrations avoided for decades," Garcia Padilla said. "We’ve achieved substantial results, including passing the first balanced budget in 22 years, achieving our target of creating 50,000 new jobs since taking office and bringing global businesses like Lufthansa to Puerto Rico."

"There is more work to be done," the governor said, "and we continue to execute on a comprehensive plan to drive economic growth and fiscal stability."

Puerto Rico’s total population decreased by 200,000 from 2000 to 2013. The Census Bureau projects that this will continue as long as 2050, and that the population may dip to 3 million then.

About 34 percent of people born in Puerto Rico live on the mainland, the study said, up from 30 percent in 1990.

“The semi-professional and professional Puerto Ricans who are moving themselves to the mainland is the result of a weak economy, violent criminal activity and lack of understanding on how to tackle the political status of the territory regarding statehood or independence,” said Rev. Miguel Rivera, the head and founder of National Coalition of Latino Clergy and Christian Leaders (CONLAMIC). “…The high criminal activity due to drug trafficking and consumption erodes the social fabric of the community, which feels frustrated because of deficient law enforcement action. Finally, lack of jobs is the main reason for such an increment in emigration numbers.”

Rivera said a different political approach needs to be considered to accelerate job creation in the island.

“An aggressive informational campaign regarding a government reduction employment and more citizenship responsibility, should be promoted to reduce excess of entitlement programs and government financial dependency," he said.

The report noted that the island’s population downturn “reverses a general pattern of growth on the island since at least the 1700s, as documented by Spanish and U.S. Census Bureau data.”

“The United States won control of Puerto Rico from Spain in 1898; the first U.S. census taken there, in 1910, counted more than 1.1 million residents. By 1990, the population had more than tripled, to 3.5 million, and peaked at 4 million in 2009. But by 2013, the island’s population had diminished to 3.6 million.”

Other patterns noted in the report are the difference between Puerto Ricans who arrived from the island since 2000 and earlier waves of Puerto Ricans.

Recent arrivals, it said, tend to head to the South, rather than the Northeast, historically a destination for Puerto Ricans.

More recent Puerto Rican arrivals are economically less well off than earlier ones were, and are more likely to live in poverty.

After a brief uptick in 2012, Puerto Rico's economy has stagnated since 2013, the report said. It said the island has a 45 percent labor force participation rate. Puerto Rico also struggles with a largely uneducated working-age population, although the number of people with a college degree increased from about 25 percent to nearly 28 percent between 2010 and 2012.

New York's Federal Reserve Bank warned in a report in July that Puerto Rico needs to improve its financial health soon or face a "painful adjustment."

The report came as the island's power company once again reached an agreement with lenders to extend a deadline to make payments on $671 million it owes to banks.

The 30-page report makes several recommendations that the New York Fed believes are needed to help push the U.S. territory out of its slump.

"The island appears to face two alternatives: either manage its own economic adjustment and put the Commonwealth on a secure fiscal basis,” it said. “Or wait for out-migration and the discipline of the market to force an even more painful adjustment, particularly for those unable or unwilling to leave the island."

The Associated Press contributed to this report.