Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 2750 | Kilograms | NA |
| 2003 | 4819 | Kilograms | 75.24% |
| 2004 | 5128 | Kilograms | 6.41% |
| 2005 | 5338 | Kilograms | 4.10% |
| 2006 | 5168 | Kilograms | -3.18% |
| 2007 | 3186 | Kilograms | -38.35% |
| 2008 | 4133 | Kilograms | 29.72% |
| 2009 | 5392 | Kilograms | 30.46% |
| 2010 | 4593 | Kilograms | -14.82% |
| 2011 | 4149 | Kilograms | -9.67% |
| 2012 | 3400 | Kilograms | -18.05% |
