Average retail gasoline prices in Tucson dropped 1.5 cents in the past week, lowering the average to $3.20 per gallon Sunday, according to a statement by GasBuddy.com, a website that tracks gasoline prices nationwide.

The city's figures are lower than the national average, which fell 0.8 cents per gallon last week to $3.36.

Tucson's average, as of Sunday, are 24.3 cents lower than one year ago.

"...gasoline prices have slowed their descent, with the national average moving just slightly lower over the last seven days," said Patrick DeHaan, senior petroleum analyst at GasBuddy.com. "The cities that had seen average gasoline prices under $3 per gallon have dried up, yet eighteen states still have at least one station selling gasoline under that level,"

The country's prices have decreased 13.7 cents during the last month, and stands 31.2 cents lower than 2012, said GasBuddy.com.