Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 1110 | Kilograms | NA |
| 2003 | 2142 | Kilograms | 92.97% |
| 2004 | 2431 | Kilograms | 13.49% |
| 2005 | 3868 | Kilograms | 59.11% |
| 2006 | 3818 | Kilograms | -1.29% |
| 2007 | 3964 | Kilograms | 3.82% |
| 2008 | 4160 | Kilograms | 4.94% |
| 2009 | 4482 | Kilograms | 7.74% |
| 2010 | 4000 | Kilograms | -10.75% |
| 2011 | 4600 | Kilograms | 15.00% |
| 2012 | 5000 | Kilograms | 8.70% |
