Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 11256 | Kilograms | NA |
| 2003 | 9362 | Kilograms | -16.83% |
| 2004 | 6951 | Kilograms | -25.75% |
| 2005 | 8871 | Kilograms | 27.62% |
| 2006 | 9628 | Kilograms | 8.53% |
| 2007 | 8818 | Kilograms | -8.41% |
| 2008 | 8406 | Kilograms | -4.67% |
| 2009 | 7217 | Kilograms | -14.14% |
| 2010 | 6394 | Kilograms | -11.40% |
| 2011 | 6513 | Kilograms | 1.86% |
| 2012 | 6973 | Kilograms | 7.06% |
