Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 3725 | Kilograms | NA |
| 2003 | 3519 | Kilograms | -5.53 % |
| 2004 | 3731 | Kilograms | 6.02 % |
| 2005 | 3236 | Kilograms | -13.27 % |
| 2006 | 1961 | Kilograms | -39.40 % |
| 2007 | 837 | Kilograms | -57.32 % |
| 2008 | 871 | Kilograms | 4.06 % |
| 2009 | 1040 | Kilograms | 19.40 % |
