Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 1851 | Metric tons | NA |
| 2004 | 5774 | Metric tons | 211.94% |
| 2005 | 11379 | Metric tons | 97.07% |
| 2006 | 8943 | Metric tons | -21.41% |
| 2007 | 8245 | Metric tons | -7.80% |
| 2008 | 10900 | Metric tons | 32.20% |
| 2009 | 2069 | Metric tons | -81.02% |
| 2010 | 7845 | Metric tons | 279.17% |
| 2011 | 21297 | Metric tons | 171.47% |
| 2012 | 20000 | Metric tons | -6.09% |
