Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 8879 | Kilograms | NA |
| 2004 | 6760 | Kilograms | -23.87% |
| 2005 | 7058 | Kilograms | 4.41% |
| 2006 | 6088 | Kilograms | -13.74% |
| 2007 | 4161 | Kilograms | -31.65% |
| 2008 | 4333 | Kilograms | 4.13% |
| 2009 | 5033 | Kilograms | 16.16% |
| 2010 | 5061 | Kilograms | 0.56% |
| 2011 | 3984 | Kilograms | -21.28% |
| 2012 | 4000 | Kilograms | 0.40% |
