Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 250 | Thousand metric tons | NA |
| 2003 | 250 | Thousand metric tons | 0.00 % |
| 2004 | 250 | Thousand metric tons | 0.00 % |
| 2005 | 250 | Thousand metric tons | 0.00 % |
| 2006 | 1488.88305664063 | Thousand metric tons | 495.55 % |
| 2007 | 1550 | Thousand metric tons | 4.10 % |
| 2008 | 1600 | Thousand metric tons | 3.23 % |
