Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 7938 | Metric tons, gross weight | NA |
| 2003 | 6000 | Metric tons, gross weight | -24.41% |
| 2004 | 76500 | Metric tons, gross weight | 1,175.00% |
| 2005 | 18042 | Metric tons, gross weight | -76.42% |
| 2006 | 90000 | Metric tons, gross weight | 398.84% |
