The U.S. economy grew 2.4% in 2015. This is the most the economy has grown in more than five years, and is a slight improvement on 2014’s 2.2% growth.

The economies of all but two states grew in 2015, some substantially more than others, and for a variety of reasons. California and Oregon each grew by 4.1%, more than any other state. Alaska and North Dakota contracted, while several states saw increases of less than 0.5%.

The professional and business services industry, the information industry, and the real estate, rental and leasing industry contributed most prominently to the nation’s growth last year.

Click here to see the states with the fastest growing economies.

Click here to see the states with the slowest growing economies.

In an interview with 24/7 Wall St., Clifford Woodruff, an economist with the Bureau of Economic Analysis, explained that the biggest drain on state economies last year was the mining sector. Indeed, the mining sectors of 34 states declined last year, including declines of at least 10% in 20 of these. He went on to say that the national decline in oil prices has likely contributed to this drop in the sector.

The impact of a suddenly weak energy industry was most apparent in North Dakota. The state had been one of the fastest growing in the country, both in terms of population and GDP over the past few years, as the development of the Bakken shale oil formation led to a substantial boom. The state had the largest economic growth of any state in four of the five years through 2014, including a 21.7% increase in 2012. In 2015, the state economy contracted by 2.1%, more than any other state.

On the whole, populations grew substantially more in the states with the fastest-growing economies, and stagnated or declined in the worst performers. Population growth exceeded 0.4% in only one of the 10 states with the weakest economies in 2015. All of the 10 states with the strongest economies surpassed the national population growth rate of 0.8%.

Woodruff explained that population growth does not necessarily lead to GDP growth, as states can import goods from other states or countries without producing more goods locally. He added, however, that it makes sense that the two figures usually move in step. “Obviously, the more people that there are, the more products, the more food, the more houses they’re going to need.”

Based on figures published by the Bureau of Economic Analysis, 24/7 Wall St. reviewed 2015 real GDP growth rates in all 50 states. The real gross domestic product measurement accounts for the effects of inflation on growth. GDP figures published by the BEA for 2015 are preliminary and subject to annual revision. Real GDP figures for past years have already been revised. Population data are from the U.S. Census Bureau and reflect estimated growth between 2014 and 2015. We also used data on poverty from the U.S. Census Bureau’s American Community Survey (ACS). Both 2014 and 2015 unemployment rates are annual averages and are from the Bureau of Labor Statistics (BLS).

These are the states with the fastest (and slowest) growing economies.