Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 16815 | Kilograms | NA |
| 2003 | 16622 | Kilograms | -1.15% |
| 2004 | 11100 | Kilograms | -33.22% |
| 2005 | 25097 | Kilograms | 126.10% |
| 2006 | 16922 | Kilograms | -32.57% |
| 2007 | 15628 | Kilograms | -7.65% |
| 2008 | 19945 | Kilograms | 27.62% |
| 2009 | 18091 | Kilograms | -9.30% |
| 2010 | 13206 | Kilograms | -27.00% |
| 2011 | 15695 | Kilograms | 18.85% |
| 2012 | 14479 | Kilograms | -7.75% |
