Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 65813 | Metric tons | NA |
| 2004 | 52483 | Metric tons | -20.25 % |
| 2005 | 20564 | Metric tons | -60.82 % |
| 2006 | 24529 | Metric tons | 19.28 % |
| 2007 | 28000 | Metric tons | 14.15 % |
| 2008 | 26000 | Metric tons | -7.14 % |
| 2009 | 25000 | Metric tons | -3.85 % |
