Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 115600 | Metric tons | NA |
| 2004 | 211278 | Metric tons | 82.77% |
| 2005 | 101186 | Metric tons | -52.11% |
| 2006 | 96469 | Metric tons | -4.66% |
| 2007 | 8631 | Metric tons | -91.05% |
| 2008 | 9180 | Metric tons | 6.36% |
| 2009 | 51895 | Metric tons | 465.31% |
| 2010 | 33465 | Metric tons | -35.51% |
| 2011 | 67703 | Metric tons | 102.31% |
| 2012 | 70000 | Metric tons | 3.39% |
