Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 102 | Thousand metric tons | NA |
| 2004 | 137 | Thousand metric tons | 34.31% |
| 2005 | 200 | Thousand metric tons | 45.99% |
| 2006 | 250 | Thousand metric tons | 25.00% |
| 2007 | 250 | Thousand metric tons | 0.00% |
