Wan-li: Year 9, Month 11, Day 27
22 Dec 1581
The annual amount of "nine-tenths pure" gold required from Yun-nan was increased by 1,000 liang. Formerly, Yun-nan did not present gold in tribute. However, beginning in the first year of the Jia-jing reign (1522/23), it presented 1,000 liang. In the 13th year (1534/35), there was an increase of 1,000 liang of fine gold, but subsequently it was ordered that this be stopped. At this time, an Imperial order was issued requiring that an additional 2,000 liang be presented. The ministry advised of the difficulties in obtaining the gold and the arduousness of presenting it in tribute....The Emperor accepted this, but as there was insufficient gold to meet the annual needs of the palace, he still required that a further amount of 1,000 liang of "nine-tenths pure" gold be presented annually.
Zhong-yang Yan-jiu yuan Ming Shi-lu, volume 101, page 2221