The Heart of Illinois saw a massive rise in gas prices last week. Gas buddy.com reports prices went up 12 cents, averaging $2.28 a gallon. That is 27 cents higher than a year ago, and 15 cents higher than it was a month ago. Experts say the unrest in Venezuela, along with the rise in crude oil prices are to blame for the rise in gas prices. The national average also went up three and a half cents to $2.31 a gallon.