Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 18070 | Metric tons | NA |
| 2004 | 10470 | Metric tons | -42.06 % |
| 2005 | 28500 | Metric tons | 172.21 % |
| 2006 | 29000 | Metric tons | 1.75 % |
| 2007 | 29000 | Metric tons | 0.00 % |
| 2008 | 29000 | Metric tons | 0.00 % |
| 2009 | 29000 | Metric tons | 0.00 % |
