Roberto Treto Rodríguez had been thinking about leaving Cuba for years. But it wasn’t until late September that he finally fled aboard a boat with 18 other Cuban migrants that reached the Florida Keys.

Thus Treto joined the ranks of more than 13,000 undocumented Cuban migrants who reached the United States, or were intercepted en route, during fiscal year 2012, which ended Sept. 30.

The figure reflects a sharp surge in the number of undocumented Cuban migrants arriving, or seeking to arrive in the United States. The figure is the largest in the last three fiscal years.

Between 2009 and 2011, the average annual number of Cuban migrants arriving or trying to arrive hovered at 7,500. Not since 2008 had the number of undocumented migrants leaving the island for the United States exceeded 10,000.

In 2008, the number of Cuban migrants who reached U.S. soil or were intercepted en route stood at 16,260.

These Cuban migrants leave without U.S. visas. Annually, the U.S. Interests Section in Havana issues 20,000 visas to Cuban nationals, who are counted separately.

The figures on undocumented Cubans came from the U.S. Coast Guard, the Border Patrol and U.S. Customs and Border Protection.

Experts on Cuba generally attributed the drop in arrivals and interceptions after 2008 to the economic crisis in the United States and improved Coast Guard interdiction methods.

There is little agreement among experts in the United States about why more Cuban migrants are arriving, but the majority seem to agree that migrant relatives in the United States may have more money to pay smugglers to get their loved ones out of the island and also that Cubans there may have grown disillusioned with the slow pace of expected economic reforms under Raúl Castro.

Three recently arrived Cuban migrants, who spoke at an office in Doral of the Church World Service resettlement service, said more Cubans want to leave the island because conditions there never improve.

Treto, 40, and Juan Alberto Rosales, 45, arrived by boat directly from Cuba, while Miguel Alfonso, 35, walked into the United States from Canada over the border near Vancouver.

Of the three men, Treto was the first to arrive aboard a boat carrying 19 people that left from Baracoa beach west of Havana on Sept. 27 and reached the Florida Keys two days later. U.S. officials picked up Treto and the other 18 men and delivered them to the Border Patrol.

Treto, from San Antonio de los Baños southwest of Havana, said he fled Cuba because of worsening economic conditions and pervasive police harassment.

“I decided to leave Cuba because I couldn’t take it anymore there,” said Treto. “I no longer found myself in that country. The economic situation, the situation of everything else, I couldn’t take. The police was always harassing me because to them everything you do is illegal.”

Treto, who was a construction worker and bicycle mechanic, had wished to leave Cuba for decades but feared taking to the sea. Ultimately, he left by boat because he couldn’t find a way to board a plane to go abroad legally. He left his wife and four children behind, and hopes to reunite with them once he gets his green card.

Under the current wet foot/dry foot policy, Cubans intercepted at sea by the U.S. Coast Guard are generally returned to the island. Those who reached U.S. soil are allowed to stay.