Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 12097 | Kilograms | NA |
| 2003 | 11119 | Kilograms | -8.08% |
| 2004 | 19240 | Kilograms | 73.04% |
| 2005 | 24120 | Kilograms | 25.36% |
| 2006 | 22561 | Kilograms | -6.46% |
| 2007 | 17473 | Kilograms | -22.55% |
| 2008 | 15184 | Kilograms | -13.10% |
| 2009 | 9803 | Kilograms | -35.44% |
| 2010 | 6037 | Kilograms | -38.42% |
| 2011 | 5703 | Kilograms | -5.53% |
| 2012 | 5995 | Kilograms | 5.12% |
