Most of Massachusetts’ population growth since 2010 has been focused in Suffolk, Middlesex and Essex counties, according to U.S. Census Bureau data released late last week.

Of the estimated 354,520-person increase in the state’s population between 2010 and 2018, 70 percent of that growth occurred in those three counties. Individually, Middlesex County gained the most, at 111,629 people, while Suffolk County gained 85,229 and Essex County gained 47,479. The next-largest growth occurred in Norfolk County, which gained 34,538 people.

In Essex County, the first quarter median single-family home sale price increased by nearly 7 percent on a year-over-year basis in 2019, to $430,000, according to data from The Warren Group, publisher of Banker & Tradesman. In Middlesex County, that figure increased by 3.79 percent to $520,000, while in Suffolk County that figure increased 2.88 percent to $535,000.

Over the last eight years, Suffolk County grew the fastest, at 11.8 percent, with Nantucket County a close second at 11.35 percent. As of July 2018, Nantucket had 11,327 residents, while Suffolk County had 807,252.

Two areas of the state – Barnstable and Berkshire counties – lost people, with the former falling by 1.15 percent to 213,413 people in 2018 and the latter falling 3.71 percent to 126,348 people.