Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 15000 | Metric tons | NA |
| 2004 | 14000 | Metric tons | -6.67% |
| 2005 | 14000 | Metric tons | 0.00% |
| 2006 | 14000 | Metric tons | 0.00% |
| 2007 | 14000 | Metric tons | 0.00% |
| 2008 | 14000 | Metric tons | 0.00% |
| 2009 | 4000 | Metric tons | -71.43% |
| 2010 | 4000 | Metric tons | 0.00% |
| 2011 | 3000 | Metric tons | -25.00% |
