Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 12210 | Kilograms | NA |
| 2003 | 12808 | Kilograms | 4.90% |
| 2004 | 12000 | Kilograms | -6.31% |
| 2005 | 10415 | Kilograms | -13.21% |
| 2006 | 10493 | Kilograms | 0.75% |
| 2007 | 10900 | Kilograms | 3.88% |
| 2008 | 10000 | Kilograms | -8.26% |
| 2009 | 6500 | Kilograms | -35.00% |
