As of July 1, 2016, Kentucky had an estimated population of 4,436,974, which is an increase of 12,363 from the prior year and an increase of 97,607, or 2.2%, since the year 2010. This includes a Population growth since the last census of 73,541 people (that is 346,968 births minus 273,427 deaths) and an increase due to net migration of 26,135 people into the state. Immigration to the United States from outside the United States resulted in a net increase of 40,051 people, and migration within the country produced a net decrease of 13,916 people. , Kentuckys population included about 149,016 foreign-born persons (3.4%). In 2016, the population density of the state was 110 people per square mile (42.5/km²).. How many people was Kentucky's population in 2015?