Arizona drivers paid an average of $4.29 on Aug. 8 for a gallon of gas, reflecting a monthly decline of 78 cents but an increase of $591 paid on an annual basis compared to gas prices a year ago, according to the Gasoline Misery Index.

The Gasoline Misery Index tracks changes in how much residents of different states pay for gasoline on an annualized basis. The index uses gas price data from the American Automobile Association (AAA) and average vehicle fuel efficiency (miles per gallon) data compiled by the U.S. Department of Energy.

The average number of vehicle miles driven by Americans is also tracked through MetroMile.com so that the Misery Index can be accurately calculated based on changing driving habits.

Nationally, the Biden Misery Index, which reflects the dollar amount the average American paid for gasoline per year since President Joe Biden took office in January 2021, is now $908.75. This financial burden is calculated using the latest average gas price data.

The spike in gas prices over the past year has pushed up Americans' overall cost of living, according to the U.S. Bureau of Statistics' Consumer Price Index, leading to inflationary pressures. But the gasoline demand has dropped in recent weeks, leading AAA to forecast continuing relief at the pump.

Higher gas prices have led to criticism of the Biden administration, with polls showing greater public disapproval of the president’s job performance. The war in Ukraine and post-pandemic supply-line pressures have also contributed to oil price volatility.