Bloomberg Intelligence economist Tom Orlik has created the following chart that shows the history of the currency over the past decade.
When it comes to the latest decision by the People's Bank of China, Orlik writes: "The PBOC's move reflects the depth of concern about China's growth, which threatens to fall below the government's 7 percent target for the year. Exports contracted 8.9 percent year on year in July as a 14 percent annual appreciation in the real effective exchange rate choked off demand."