Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 44660 | Metric tons | NA |
| 2004 | 40776 | Metric tons | -8.70% |
| 2005 | 38000 | Metric tons | -6.81% |
| 2006 | 45000 | Metric tons | 18.42% |
| 2007 | 35000 | Metric tons | -22.22% |
| 2008 | 11100 | Metric tons | -68.29% |
| 2009 | 2814 | Metric tons | -74.65% |
| 2010 | 2050 | Metric tons | -27.15% |
| 2011 | 3000 | Metric tons | 46.34% |
| 2012 | 3000 | Metric tons | 0.00% |
