Auburn rolled out the welcome mat, just not a whole lot.

The city gained six people in a new population estimate released by the U.S. Census on Thursday. The figures show Lewiston losing five people, Bangor losing 163 and Portland gaining 75.

In the 22 Maine cities and towns included in the count, Saco’s population increased the most from 2011 to 2012 at 131 people. Bangor’s declined the most.

Jim McConnon, a professor of economics at the University of Maine, cautioned that the numbers are estimates. He argued that with such minor changes, growth was basically flat, but that the small shifts fit in with larger trends: an aging state, growth centralized in a handful of southern and coastal counties and a move to larger cities.

“(Maine has) an economy that’s kind of stuck in neutral,” McConnon said. “The population is a very important driver in the economy in a number of ways.”

Lincoln Jeffers, Lewiston’s economic and community development director, suspects his city was under-counted.

“Immigrants can be difficult to capture in census activity,” Jeffers said. “(General Assistance) continues to see new immigrant families, with relocating immigrants perhaps at a slightly slower pace than in the past, but with an increasing number of asylum seekers. Enrollment in the schools is holding steady and perhaps trending up a little.”

As a whole, Maine was estimated to have grown by 648 people to a population of 1,329,192.

Around New England, Massachusetts gained 39,141; Connecticut, 3,630; New Hampshire, 2,911. Vermont lost 581 and Rhode Island lost 354.

“(In Massachusetts), I think you have a much more diversified economy with much larger numbers and probably a greater churn in the job market,” McConnon said.

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