Reversing a three-year trend downward, the number of undocumented Cubans intercepted at sea or who reached U.S. shores in the past 12 months soared by more than 100 percent — sparking questions about the reasons behind the new trend.

About 1,700 Cubans were interdicted or landed in fiscal year 2011, which ended Sept. 30, according to figures compiled by El Nuevo Herald from Homeland Security Department agencies. That compares to 831 in fiscal 2010.

U.S. Coast Guard interdictions at sea rose from 422 to 1,000, while landings on U.S. shores climbed from 409 to almost 700. Meanwhile, arrivals at U.S. border posts — almost all from Mexico — barely changed from 6,219 to 6,300.

The figures reflected the first hike since fiscal year 2007, when the total hit 19,710, up from 16,226 for fiscal 2006. The number dropped back to 16,260 in 2008 and plummeted to 8,113 the following year.

While the uptick over the past year would seem relatively modest, the reversal of the downward trend and the growth of 14 percent in the overall figure has triggered much speculation on exactly what drove the increase.

Arturo Cobo, a Key West businessman who is in regular contact with some of the undocumented migrants and their families, said that the island’s stalled economy is leading many Cubans to try to seek better lives abroad.

Havana activist Elizardo Sánchez agreed. “The economy is worse each day. Less money, less food, less everything,” said the head of the illegal but tolerated Cuban Commission for Human Rights and National Reconciliation.

Havana blogger Orlando Luis Pardo Lazo said perhaps the uptick is simply a part of “the natural tendency of the Cuban anthropology — to escape — a process in which the numbers drop but the pressures accumulate, and then the numbers grow.”

Raúl Castro’s government also may be “turning a blind eye to some of the departures as an escape valve for the growing discontent,” Cobo noted, referring to the increasing number of dissident protests over the past two years.

Also possible, he added, is that the easing of the U.S. economic crisis made it easier for Cuban Americans to pay the fees demanded by smugglers to bring relatives and friends from the island, usually about $10,000 a head.

The increase in attempts by undocumented Cubans to reach the United States appears to be in line with the Cuban government’s own figures, which show that legal emigration grew by 3 percent from 2009 to 2010.

With a population of 11.2 million, Cuba recorded 38,165 legal emigrations last year, compared to 36,564 in 2009, according to a report this summer by the National Office for Statistics (ONE).

Indeed, about 318,000 Cubans arrived in the United States both legally and illegally between 2000 and 2009, according to a recent study by Jorge Duany, a professor at the University of Puerto Rico who tracks the Cuban Diaspora.

There’s little doubt that large numbers of Cubans want to leave the communist-ruled island, according to a 2009 dispatch written by U.S. diplomats in Havana and provided by WikiLeaks to McClatchy, which owns El Nuevo Herald.

“Emigration remains a virtual obsession with many Cubans, especially, but by no means exclusively, with the young,” the cable noted. “Much of the Cuban public [is] still eager to leave the island.”