Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 11883 | Metric tons | NA |
| 2004 | 5646 | Metric tons | -52.49 % |
| 2005 | 25078 | Metric tons | 344.17 % |
| 2006 | 11504 | Metric tons | -54.13 % |
| 2007 | 18618 | Metric tons | 61.84 % |
