Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 65833 | Metric tons | NA |
| 2004 | 187465 | Metric tons | 184.76% |
| 2005 | 70600 | Metric tons | -62.34% |
| 2006 | 70000 | Metric tons | -0.85% |
| 2007 | 90889 | Metric tons | 29.84% |
| 2008 | 90000 | Metric tons | -0.98% |
| 2009 | 66383 | Metric tons | -26.24% |
| 2010 | 95767 | Metric tons | 44.26% |
| 2011 | 58887 | Metric tons | -38.51% |
| 2012 | 60000 | Metric tons | 1.89% |
| 2013 | 60000 | Metric tons | 0.00% |
