Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 15469 | Kilograms | NA |
| 2003 | 12564 | Kilograms | -18.78% |
| 2004 | 21330 | Kilograms | 69.77% |
| 2005 | 14023 | Kilograms | -34.26% |
| 2006 | 11354 | Kilograms | -19.03% |
| 2007 | 6750 | Kilograms | -40.55% |
| 2008 | 3579 | Kilograms | -46.98% |
| 2009 | 4965 | Kilograms | 38.73% |
| 2010 | 9100 | Kilograms | 83.28% |
| 2011 | 12824 | Kilograms | 40.92% |
| 2012 | 14742 | Kilograms | 14.96% |
