Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 4192 | Kilograms | NA |
| 2003 | 8769 | Kilograms | 109.18% |
| 2004 | 8268 | Kilograms | -5.71% |
| 2005 | 7456 | Kilograms | -9.82% |
| 2006 | 5200 | Kilograms | -30.26% |
| 2007 | 4440 | Kilograms | -14.62% |
| 2008 | 4527 | Kilograms | 1.96% |
| 2009 | 4857 | Kilograms | 7.29% |
| 2010 | 4476 | Kilograms | -7.84% |
| 2011 | 4611 | Kilograms | 3.02% |
| 2012 | 4285 | Kilograms | -7.07% |
