Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 500 | Metric tons | NA |
| 2004 | 550 | Metric tons | 10.00% |
| 2005 | 550 | Metric tons | 0.00% |
| 2006 | 560 | Metric tons | 1.82% |
| 2007 | 570 | Metric tons | 1.79% |
| 2008 | 570 | Metric tons | 0.00% |
| 2009 | 580 | Metric tons | 1.75% |
