Illinois gas prices have decreased 2.2 cents per gallon this week, averaging state prices at $3.49 per gallon compared to the national average of $3.37 per gallon around the country according to GasBuddy.

Within a month, Illinois gas prices have dropped 3.8 cents per gallon and stand at 21.1 cents per gallon lower than last year.

GasBuddy reports that the cheapest gas station in Illinois sells for $2.99 per gallon while the most expensive price has remained $4.79 per gallon for the third week.

The recent decline has Patrick De Haan, head of petroleum analysis at GasBuddy, commenting on possible economic changes that could be playing a role in the drop of gas prices.

“We’ve seen some refinery challenges in pockets of the country, while others are starting the transition to summer gasoline, weighing on prices,” De Haan said. “Oil prices have softened over the last week, helping to limit any upside at the pump, with strong economic data leading to concern that the Fed will continue to use interest rates to slow the economy.”