Task 1 Trend [我的练笔]

As is shown in the first graph, the upward trend of Billions of dollars can be categorized into three stages. It fluctuated between about $36 billion to $50 billion from 1956 to 1965 and there is a surge from approximate $46 billion in 1965 to $80 billion in 1970. After 1970, it fluctuated, bottoming out at nearly $75 billion and reaching a peak at around $85 billion in 1975.