Historically, the gold-silver ratio has shown a gradual widening trend. During the early Ming Dynasty, the official exchange rate was about 1:4, fluctuating between 1:4 and 1:7.5; in the mid-Ming period, due to the influx of overseas silver, one tael of gold could be exchanged for 7-8 taels of silver; by the end of the Ming Dynasty, the ratio rose to 1:13. During the Kangxi and Qianlong periods of the Qing Dynasty, the gold-silver ratio remained relatively stable, with one tael of gold roughly equivalent to 10-12 taels of silver; from the Kangxi to Jiaqing years, the ratio fluctuated around 1:15; in the late Qing, due to large-scale outflow of silver, the ratio soared, reaching 1:15 - 1:20 during the Xianfeng and Tongzhi years, and exceeding 1:30 by the end of the Guangxu period.