Average retail gasoline prices in Nevada have risen 11.8 cents per gallon in the past week, averaging $3.81 a gallon on Saturday, according to GasBuddy's daily survey of 1,130 gas outlets in Nevada. This compares with the national average that has increased 2.9 cents per gallon in the last week to $3.72/g, according to gasoline price website GasBuddy.com.Including the change in gas prices in Nevada during the past week, prices yesterday were 8.9 cents per gallon higher than the same day one year ago and are 68.6 cents per gallon higher than a month ago. The national average has increased …