The Nauruan economy peaked in the mid-1970s, when its GDP per capita was estimated to be US$50,000, second only to Saudi Arabia. Most of this came from phosphate mining, which declined from the early 1980s. There are few other resources, and most necessities are imported. Small-scale mining is still conducted by RONPhos, formerly known as the Nauru Phosphate Corporation. The government places a percentage of RONPhos's earnings into the Nauru Phosphate Royalties Trust. The trust manages long-term investments, which were intended to support the citizens after the phosphate reserves were exhausted.