(Portland, OR) -- Gas prices in Oregon continued to decline over the last week. Triple-A reports Oregon's average price for a gallon of gas fell 13 cents to four-56, while the national average declined six cents to three-79. Oregon's average is still 54 cents higher than this time last year. Iran continues to attack ships in the Strait of Hormuz which caused oil prices to increase on Tuesday, and that could affect gas prices if oil prices remain higher.