The average price of a gallon of regular gasoline nationwide went down again in the past week. Gas went down from $2.22 per gallon to $2.18, while it was at $3.02 per gallon one year ago.  There was large decrease in Illinois for the past week, as it went down from $2.40 per gallon of regular gas to $2.31.  It was also down significantly in Nashville going from $2.19 per gallon of regular gas to $2.09 per gallon.