 In 2014, about two-thirds (66%) had been in the U.S. for ten years or more, while just 14% had been in the U.S. for less than five years.Just as the total population of illegal immigrants in the U.S. has declined since 2007, the proportion of illegal immigrants in the workforce has also declined; in 2012, illegal immigrants made up 5.1% of the U.S.'s civilian labor force.Unauthorized immigrant workers are over-represented in certain economic sectors, making up 26% of farming, fisheries, and forest workers; 17% of cleaning, maintenance, and groundskeeping workers; 14% of construction workers; and 11% of food preparation workers.