Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 218676 | Metric tons | NA |
| 2004 | 270994 | Metric tons | 23.92% |
| 2005 | 255334 | Metric tons | -5.78% |
| 2006 | 255622 | Metric tons | 0.11% |
| 2007 | 22000 | Metric tons | -91.39% |
| 2008 | 35000 | Metric tons | 59.09% |
| 2009 | 35000 | Metric tons | 0.00% |
