Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 30 | Thousand metric tons | NA |
| 2003 | 200 | Thousand metric tons | 566.67 % |
| 2004 | 170 | Thousand metric tons | -15.00 % |
| 2005 | 150 | Thousand metric tons | -11.76 % |
| 2006 | 150 | Thousand metric tons | 0.00 % |
| 2007 | 270 | Thousand metric tons | 80.00 % |
| 2008 | 270 | Thousand metric tons | 0.00 % |
