Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 61379 | Kilograms | NA |
| 2003 | 67832 | Kilograms | 10.51 % |
| 2004 | 73670 | Kilograms | 8.61 % |
| 2005 | 68483 | Kilograms | -7.04 % |
| 2006 | 58349 | Kilograms | -14.80 % |
| 2007 | 65000 | Kilograms | 11.40 % |
| 2008 | 68000 | Kilograms | 4.62 % |
| 2009 | 66000 | Kilograms | -2.94 % |
