Venezuelans for the first time led asylum requests to the United States as the country's middle class fled the crashing, oil-dependent economy.

Data from the U.S. government's Citizenship and Immigration Services show that 18,155 Venezuelans submitted asylum requests last year, a 150 percent increase over 2015 and six times the level seen in 2014. China was second place, with 17,745 requests coming from citizens of that country.

Venezuela first cracked the top 10 asylum-seeking nations following months of sometimes bloody street protests in early 2014 seeking to oust President Nicolas Maduro.

But back then, amid the widespread jailing and harassment of opponents of the socialist administration, fewer than 100 Venezuelans per month sought asylum. That compares with 2,334 requests in December, 2016, the last month for which data is available.

The number of applicants has skyrocketed since December 2015, when the opposition took control of congress in a landslide election, giving hope to many that it could disrupt 17 years of socialist rule. Instead of reaching out to his opponents, Maduro retrenched and more and more Venezuelans began to uproot as triple-digit inflation pulverized salaries and widespread food and medicine shortages made life unbearable for many.

The vast majority leaving are middle-class Venezuelans who don't qualify for refugee status reserved for those seeking to escape political persecution, according to Julio Henriquez, director of the Boston-based nonprofit Refugee Freedom Program, which has been drawing attention to the trend.

"The pace at which requests are increasing is alarming," said Henriquez, whose group obtained the still-unpublished data in a Feb. 8 meeting between U.S. officials and immigration lawyers. "It's not just worrisome that so many people are escaping the terrible situation in Venezuela but also that the practice of sending asylum-seekers with poor advice and false proof is proliferating."

Still, given mounting hardships at home, increasing numbers of Venezuelans are willing to take advantage of a more-than-two-year delay for their applications to be processed to obtain work authorization and seek short-term employment even if it means being eventually deported.

In the 2015 fiscal year, Venezuela was among the top 10 countries whose citizens had overstayed their visas in the United States, according to an estimate of visa overstays by the Department of Homeland Security.

Venezuelans seeking U.S. asylum represent a small share of the overall Venezuelan immigrant population, some of whom have made their home in the U.S. for decades.