As of 2015, Connecticut had an estimated population of 3,590,886, which is an decrease of 5,791, or -0.16%, from the prior year and an increase of 16,789, or 0.47%, since the year 2010. This includes a natural increase since the last census of 67,427 people (that is 222,222 births minus 154,795 deaths) and an increase due to net migration of 41,718 people into the state. Immigration to the United States from outside the United States resulted in a net increase of 75,991 people, and Human migration within the country produced a net loss of 34,273 people. Based on the 2005 estimates, Connecticut moved from the 29th most populous state to 30th. 2016 estimates put Connecticuts population at 3,576,452.. Was the estimated population of Connecticut higher in 2015 or 2010?