Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2004 | 34000 | Metric tons | NA |
| 2005 | 89785 | Metric tons | 164.07% |
| 2006 | 94500 | Metric tons | 5.25% |
| 2007 | 85105 | Metric tons | -9.94% |
| 2008 | 85000 | Metric tons | -0.12% |
| 2009 | 80000 | Metric tons | -5.88% |
| 2009 | 50000 | Metric tons | -37.50% |
| 2010 | 50000 | Metric tons | 0.00% |
| 2011 | 50000 | Metric tons | 0.00% |
| 2012 | 50000 | Metric tons | 0.00% |
| 2013 | 80000 | Metric tons | 60.00% |
