Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 2815 | Kilograms | NA |
| 2003 | 2508 | Kilograms | -10.91% |
| 2004 | 2205 | Kilograms | -12.08% |
| 2005 | 2703 | Kilograms | 22.59% |
| 2006 | 2790 | Kilograms | 3.22% |
| 2007 | 2496 | Kilograms | -10.54% |
| 2008 | 2126 | Kilograms | -14.82% |
| 2009 | 2022 | Kilograms | -4.89% |
| 2010 | 2675 | Kilograms | 32.29% |
| 2011 | 2053 | Kilograms | -23.25% |
| 2012 | 2302 | Kilograms | 12.13% |
