Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 8730 | Metric tons | NA |
| 2004 | 14769 | Metric tons | 69.18% |
| 2005 | 12357 | Metric tons | -16.33% |
| 2006 | 12500 | Metric tons | 1.16% |
| 2007 | 12500 | Metric tons | 0.00% |
| 2008 | 7229 | Metric tons | -42.17% |
| 2009 | 5105 | Metric tons | -29.38% |
| 2010 | 6628 | Metric tons | 29.83% |
| 2011 | 7348 | Metric tons | 10.86% |
| 2012 | 7520 | Metric tons | 2.34% |
| 2013 | 7148 | Metric tons | -4.95% |
