Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 5459 | Metric tons | NA |
| 2004 | 6231 | Metric tons | 14.14% |
| 2005 | 5362 | Metric tons | -13.95% |
| 2006 | 5517 | Metric tons | 2.89% |
| 2007 | 12367 | Metric tons | 124.16% |
| 2008 | 8447 | Metric tons | -31.70% |
| 2009 | 11567 | Metric tons | 36.94% |
| 2010 | 11951 | Metric tons | 3.32% |
| 2011 | 12000 | Metric tons | 0.41% |
| 2012 | 12000 | Metric tons | 0.00% |
| 2013 | 12000 | Metric tons | 0.00% |
