Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 5000 | Metric tons | NA |
| 2004 | 6000 | Metric tons | 20.00% |
| 2005 | 6000 | Metric tons | 0.00% |
| 2006 | 6300 | Metric tons | 5.00% |
| 2007 | 5000 | Metric tons | -20.63% |
| 2008 | 5000 | Metric tons | 0.00% |
| 2009 | 19400 | Metric tons | 288.00% |
| 2010 | 19000 | Metric tons | -2.06% |
| 2011 | 19000 | Metric tons | 0.00% |
| 2012 | 20000 | Metric tons | 5.26% |
