You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
1973_oil_crisis

Context:
OPEC soon lost its preeminent position, and in 1981, its production was surpassed by that of other countries. Additionally, its own member nations were divided. Saudi Arabia, trying to recover market share, increased production, pushing prices down, shrinking or eliminating profits for high-cost producers. The world price, which had peaked during the 1979 energy crisis at nearly $40 per barrel, decreased during the 1980s to less than $10 per barrel. Adjusted for inflation, oil briefly fell back to pre-1973 levels. This "sale" price was a windfall for oil-importing nations, both developing and developed.

Question:
Which year did the price of oil drop to $10 per barrel?

1980s