Maine’s economic order was upended last year, with two of the northernmost Maine counties posting the fastest growth in the state in personal income and Aroostook County more than tripling the national average.

Aroostook County’s personal income grew by 4.4 percent in 2013, well above the national average for the year of 1.3 percent, and partially fueled by a growing farming community. In neighboring Piscataquis County, which has been Maine’s poorest county for several years, personal income rose by 4.2 percent, ranking second in the state, according to county and metropolitan figures released Tuesday by the Bureau of Economic Analysis.

Overall, Maine’s personal income rose a healthy 2.7 percent, slightly more than twice the national average, led by the retail, finance and insurance sectors as well as personal transfer receipts, a measure of government payments, including those for Social Security, Medicare and Medicaid. Transfer receipts grew by 6.2 percent in Maine, compared with 2.7 percent nationally.

By contrast, southern Maine’s normally more robust income gains flagged. Cumberland County’s personal income grew 2.1 percent, 13th in the state, and York County’s grew by 1.8 percent, next-to-last in the state. Sagadahoc County’s personal income, which grew by 3.4 percent in 2012, saw that growth rate halved last year and fell to the bottom in growth for Maine’s 16 counties.

James Breece, an economics professor at the University to Southern Maine, said the northern tier of the state has had solid, but not spectacular, economic growth since the 2008-09 recession and he suggested the figures reflect the ongoing exodus of people from the state’s northern counties.

He said that Aroostook County’s population dropped by more than 1 percent last year and many of those leaving were likely frustrated job-seekers, whose earnings – or lack of income – would have dragged down the county’s average per capita income of $36,647 if they had stayed. He said some of those leaving northern Maine are likely headed for the southern part of the state – Cumberland County’s population grew to 285,456 last year – where low-income job seekers might find work, but at less than the county’s average personal income of $49,472.

“If you have people moving out of a county, especially if they’re moving because they haven’t been able to find a job or are just entering the workforce and so are on the low end of the income scale, that can actually result in a higher per capita personal income for that county,” said Amanda Rector, Maine’s state economist.

For instance, Aroostook County’s per capita personal income was $35,807 in 2012 and the increase in 2013 of about $1,500 produced a robust percentage jump. In Cumberland County, the increase of slightly more than $1,000 on top of the 2012 per capita personal income of $48,451 created a percentage increase that was less impressive.

Rector also said wage increases in Cumberland County were still strong and ranked third in the state on their own, but figures from Aroostook and Piscataquis counties were swayed by a very strong showing in proprietor income, or earnings from small businesses. She said that figure jumped 14.9 percent in Aroostook County and 7.1 percent in Piscataquis County.

The measure only accounts for about 10 percent of personal income, she said, but is very volatile – overall proprietor income in Maine, including the two northern counties, grew by 6.1 percent.

Farm income is also a small component of personal income, but it increased nearly 60 percent in Aroostook County.

Farm income was also strong elsewhere in Maine, growing more than 12 percent.

The BEA’s figures for metro areas also reflect a reversal of the normal order. Bangor led with an increase in personal income of 2.8 percent, 39th among the 389 metro areas nationally. Lewiston-Auburn was second in the state, with an increase of 2.3 percent, which ranked 64th nationally, and Portland was last in the state with an increase of 2.0 percent, 88th nationally.