From the early twentieth century to the 1970s, the major oil discoveries and improved production techniques meant that:
This refers to the economic principle which states that if there is an increase in demand of a particular good or product, then there would be an increase in price.
With this in mind, we can see that from the early 20th Century, there was an increase in oil discoveries which made the production techniques to improve and this meant that because of the increase in supply, there was a decline in price.
Read more about demand and supply here:
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