I want to know the answer to the following question:
How many Pillar industries were there from the 1960s to the 1980s?
All the background I'm provided with is that "Overenthusiastic in building a “world-class” industrial city, the government also made many disastrous mistakes during development, such as spending hundreds of millions of yuan to mine for non-existent coal, resulting in negative economic growth in the late 1960s.". Is that enough to answer the question?
Answer: no