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% |
| 2010 | 1856 | Kilograms | 78.46% |
| 2011 | 1661 | Kilograms | -10.51% |
| 2012 | 1636 | Kilograms | -1.51% |
