Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2004 | 3 | Thousand metric tons | NA |
| 2005 | 1.29999995231628 | Thousand metric tons | -56.67% |
| 2006 | 1.29999995231628 | Thousand metric tons | 0.00% |
| 2007 | 0.651000022888184 | Thousand metric tons | -49.92% |
