Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 7200 | Metric tons | NA |
| 2004 | 10500 | Metric tons | 45.83% |
| 2005 | 8000 | Metric tons | -23.81% |
| 2006 | 5500 | Metric tons | -31.25% |
| 2007 | 5600 | Metric tons | 1.82% |
| 2008 | 5600 | Metric tons | 0.00% |
