Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 4000 | Metric tons | NA |
| 2004 | 4000 | Metric tons | 0.00% |
| 2005 | 231585 | Metric tons | 5,689.63% |
| 2006 | 242264 | Metric tons | 4.61% |
| 2007 | 240310 | Metric tons | -0.81% |
| 2008 | 251412 | Metric tons | 4.62% |
| 2009 | 209172 | Metric tons | -16.80% |
