Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 65833 | Metric tons | NA |
| 2004 | 187465 | Metric tons | 184.76 % |
| 2005 | 70600 | Metric tons | -62.34 % |
| 2006 | 70000 | Metric tons | -0.85 % |
| 2007 | 90889 | Metric tons | 29.84 % |
| 2008 | 90000 | Metric tons | -0.98 % |
| 2009 | 90000 | Metric tons | 0.00 % |
