Context: One wave of the population boom ended abruptly in the mid-1980s, as oil prices fell precipitously. The space industry also suffered in 1986 after the Space Shuttle Challenger disintegrated shortly after launch. There was a cutback in some activities for a period. In the late 1980s, the city's economy suffered from the nationwide recession. After the early 1990s recession, Houston made efforts to diversify its economy by focusing on aerospace and health care/biotechnology, and reduced its dependence on the petroleum industry. Since the increase of oil prices in the 2000s, the petroleum industry has again increased its share of the local economy.

Question: In what year did the space shuttle Challenger explode after launch?
Answer: 1986

Question: Why did Houston's economy have problems in the late 1980's?
Answer: the nationwide recession

Question: In the 1990's, what is something Houston did to try to diversify it's economy?
Answer: reduced its dependence on the petroleum industry

Question: The petroleum industry has become a larger part of Houston's economy again for what reason?
Answer: the increase of oil prices in the 2000s

Question: What caused population growth to decline  in the 1980s?
Answer: oil prices fell

Question: Which shuttle disintegrated in 1986 to cause a decline in the space industry?
Answer: Space Shuttle Challenger

Question: When did Houston suffer an economic decline?
Answer: late 1980s

Question: What did Houston focus on after the 1990s recession to improve its economy?
Answer: aerospace and health care

Question: When did Houston begin to regain its dependence on the oil industry?
Answer: 2000s

Question: In what year did the space shuttle Challenger succeed after launch?
Answer: Unanswerable

Question:  Why didn't Houston's economy have problems in the late 1980's?
Answer: Unanswerable

Question: In the 1990's, what is something Houston did to try not to diversify it's economy?
Answer: Unanswerable

Question: The petroleum industry did not become a larger part of Houston's economy again for what reason?
Answer: Unanswerable