The Energy Information Administration (EIA) said this week Ohio and Pennsylvania each increased natural gas production by about 1.2 Bcf/d last year at a time when annual U.S. gas output declined for the first time since 2005.

While Louisiana, West Virginia and North Dakota posted gains last year as well, the increases were well below 1 Bcf/d. Texas, the nation’s leading gas producing state, saw production decline by 2.5 Bcf/d in 2016. U.S. gas production dropped to 77 Bcf/d last year from 79 Bcf/d in 2015.

Pennsylvania and Ohio had the two largest annual gas production increases from 2015 to 2016, reflecting sustained volumes from the Utica and Marcellus shales. The formations, EIA said, have accounted for 85% of U.S. shale gas output growth since 2012. Production from both states has accounted for an increasing share of the nation’s total in recent years, going from less than 2% in 2006 to about one-quarter in 2016.

Pennsylvania surpassed Louisiana in 2013 to become the country’s second-highest natural gas producing state. Ohio vaulted over West Virginia last year to become the seventh-highest gas producing state. Ohio produced about 1.4 Tcf of natural gas last year, almost entirely from the Utica, while shale drillers in Pennsylvania produced 5.1 Tcf, according to state data.

EIA’s Today in Energy note also said Louisiana’s 2016 increase, mostly from the Haynesville Shale, was its first since 2011, while West Virginia and North Dakota have had 13 and 8 consecutive years of natural gas production increases, respectively. EIA’s Short-Term Energy Outlook projects that Lower 48 gas production will increase in both 2017 and 2018 as gas prices rise and result in more rig activity.