Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 3400 | Kilograms | NA |
| 2003 | 3400 | Kilograms | 0.00% |
| 2004 | 5900 | Kilograms | 73.53% |
| 2005 | 7900 | Kilograms | 33.90% |
| 2006 | 8100 | Kilograms | 2.53% |
| 2007 | 7100 | Kilograms | -12.35% |
| 2008 | 7900 | Kilograms | 11.27% |
| 2009 | 5580 | Kilograms | -29.37% |
| 2010 | 6100 | Kilograms | 9.32% |
| 2011 | 8610 | Kilograms | 41.15% |
| 2012 | 7910 | Kilograms | -8.13% |
| 2013 | 7110 | Kilograms | -10.11% |
