You need to do more research. Again, quickly: during the 70s (by the way, it's not possessive; it's plural)the price of gasoline in the US more than doubled. Imported supply decreased about 18%. For the first time, Americans invested in large numbers in small vehicles and significantly affected demand. Price controls were placed on gasoline on and off during the decade, and gas rationing was in effect.

Why in the world can't some people get it through their head that dollars chase products and that the amount of dollars chasing a product will determine its price. Its competition and its called demand.