Average retail gasoline prices in Nevada have fallen 4.7 cents per gallon in the past week, averaging $3.61 a gallon on Sunday. This compares with the national average that has fallen 3.2 cents per gallon in the last week to $3.43 a gallon, according to gasoline price website NevadaGasPrices.com.Including the change in gas prices in Nevada during the past week, prices yesterday were 8.1 cents per gallon higher than the same day one year ago and are 30.7 cents per gallon lower than a month ago. The national average has decreased 26.4 cents per gallon during the last month and …