Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 90000 | Kilograms | NA |
| 2003 | 90000 | Kilograms | 0.00 % |
| 2004 | 93000 | Kilograms | 3.33 % |
| 2005 | 90000 | Kilograms | -3.23 % |
| 2006 | 85000 | Kilograms | -5.56 % |
| 2007 | 85000 | Kilograms | 0.00 % |
| 2008 | 85000 | Kilograms | 0.00 % |
| 2009 | 90000 | Kilograms | 5.88 % |
