Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 4374 | Metric tons | NA |
| 2004 | 2993 | Metric tons | -31.57 % |
| 2005 | 4201 | Metric tons | 40.36 % |
| 2006 | 1961 | Metric tons | -53.32 % |
| 2007 | 2104 | Metric tons | 7.29 % |
| 2008 | 2108 | Metric tons | 0.19 % |
| 2009 | 2000 | Metric tons | -5.12 % |
