"............ the price of oil increased from around $3/b in the early 1970s to more than $40/b in the early 1980s. It decreased to a single digit in the mid-1980s only to increase to more than $40/b again after the Iraqi invasion of Kuwait. Prices declined to a single digit again in early 1999, only to exceed $55/b in June 2005." Read on: The Optimal Price of OPEC’s Oil- A F Alhajji