Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2005 | 30480 | Metric tons | NA |
| 2006 | 60803 | Metric tons | 99.48% |
| 2008 | 24929 | Metric tons | -59.00% |
| 2009 | 54019 | Metric tons | 116.69% |
| 2010 | 67806 | Metric tons | 25.52% |
| 2011 | 59897 | Metric tons | -11.66% |
| 2012 | 60000 | Metric tons | 0.17% |
