The national gas price of unleaded gas remained flat at $2.49 from last week, maintaining what were the highest gas prices to start the year since 2014, according to AAA.

The average price for gas is 12 cents more expensive than the same time in 2017, though consumer demand has declined. If this trend continues, gas prices should start to decrease, according to Jeanette Casselano, AAA spokesperson.

States with the largest monthly changes include Alaska (down 13 cents), New Mexico (down 11 cents), Colorado (up 10 cents), Illinois (up 9 cents), Delaware (up 9 cents), Idaho (down 9 cents), Michigan (up 9 cents), Utah (down 8 cents), Wyoming (down 8 cents) and Maryland (up 7 cents), according to AAA.

States with the least expensive gasoline include Missouri ($2.22), Arkansas ($2.24), Oklahoma ($2.25), South Carolina ($2.25), Alabama ($2.25), Texas ($2.25), Mississippi ($2.26), Louisiana ($2.27), Tennessee ($2.28) and Kansas ($2.28), AAA also reported.

Meanwhile, the price of a gallon of diesel increased 2 cents on the week to $2.996, which is 39.9 cents higher than a year ago, according to the U.S. Energy Information Administration.