Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 20823 | Kilograms | NA |
| 2003 | 46515 | Kilograms | 123.38% |
| 2004 | 37738 | Kilograms | -18.87% |
| 2005 | 35783 | Kilograms | -5.18% |
| 2006 | 15683 | Kilograms | -56.17% |
| 2007 | 15482 | Kilograms | -1.28% |
| 2008 | 34321 | Kilograms | 121.68% |
| 2009 | 47837 | Kilograms | 39.38% |
| 2010 | 53605 | Kilograms | 12.06% |
| 2011 | 55908 | Kilograms | 4.30% |
| 2012 | 66178 | Kilograms | 18.37% |
