Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 4640 | Metric tons | NA |
| 2004 | 3037 | Metric tons | -34.55% |
| 2005 | 3150 | Metric tons | 3.72% |
| 2006 | 4399 | Metric tons | 39.65% |
| 2007 | 4321 | Metric tons | -1.77% |
| 2008 | 4822 | Metric tons | 11.59% |
| 2009 | 301 | Metric tons | -93.76% |
