sentences:  Curbs on immigration however began to be implemented in the 2010s to ease increasing social issues arising from the high level of immigration.The high level of foreign migrant workers in late 20th and early 21st centuries meant that Singapore has one of the highest percentages of foreigners in the world.By the middle of the 2010s, nearly 40% of the population were estimated to be of foreign origin; although many have become permanent residents, most of them were non-citizens made up of foreign students and workers including dependants.