Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 27000 | Kilograms | NA |
| 2003 | 30000 | Kilograms | 11.11% |
| 2004 | 30000 | Kilograms | 0.00% |
| 2005 | 18062 | Kilograms | -39.79% |
| 2006 | 20000 | Kilograms | 10.73% |
| 2007 | 22000 | Kilograms | 10.00% |
| 2008 | 20825 | Kilograms | -5.34% |
| 2009 | 22839 | Kilograms | 9.67% |
| 2010 | 30272 | Kilograms | 32.55% |
| 2011 | 36846 | Kilograms | 21.72% |
| 2012 | 40006 | Kilograms | 8.58% |
