Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 10082 | Metric tons | NA |
| 2004 | 10000 | Metric tons | -0.81 % |
| 2005 | 10000 | Metric tons | 0.00 % |
| 2006 | 2967 | Metric tons | -70.33 % |
| 2007 | 1513 | Metric tons | -49.01 % |
| 2008 | 1500 | Metric tons | -0.86 % |
| 2009 | 1500 | Metric tons | 0.00 % |
