Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 27369 | Metric tons | NA |
| 2004 | 20601 | Metric tons | -24.73% |
| 2005 | 23000 | Metric tons | 11.65% |
| 2006 | 20000 | Metric tons | -13.04% |
| 2007 | 9000 | Metric tons | -55.00% |
| 2008 | 12000 | Metric tons | 33.33% |
| 2009 | 15000 | Metric tons | 25.00% |
| 2010 | 22000 | Metric tons | 46.67% |
| 2011 | 25000 | Metric tons | 13.64% |
| 2012 | 25000 | Metric tons | 0.00% |
