Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 1724 | Metric tons | NA |
| 2004 | 2688 | Metric tons | 55.92% |
| 2005 | 2574 | Metric tons | -4.24% |
| 2006 | 3512 | Metric tons | 36.44% |
| 2007 | 3500 | Metric tons | -0.34% |
| 2008 | 3500 | Metric tons | 0.00% |
| 2009 | 3600 | Metric tons | 2.86% |
| 2010 | 2475 | Metric tons | -31.25% |
| 2011 | 8426 | Metric tons | 240.44% |
| 2012 | 11251 | Metric tons | 33.53% |
| 2013 | 243 | Metric tons | -97.84% |
