Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 740 | Metric tons | NA |
| 2004 | 760 | Metric tons | 2.70% |
| 2005 | 780 | Metric tons | 2.63% |
| 2006 | 780 | Metric tons | 0.00% |
| 2007 | 830 | Metric tons | 6.41% |
