Illinois, December 19- Average retail gasoline prices in Illinois have fallen 6.2 cents per gallon in the past week, averaging $3.29/g yesterday. This compares with the national average that has fallen 4.3 cents per gallon in the last week to $3.23/g, according to gasoline price website IllinoisGasPrices.com.

Including the change in gas prices in Illinois during the past week, prices yesterday were 20.8 cents per gallon higher than the same day one year ago and are 18.4 cents per gallon lower than a month ago. The national average has decreased 13.4 cents per gallon during the last month and stands 26.4 cents per gallon higher than this day one year ago.